diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesDatasetDriftDetectedEventData.Serialization.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesDatasetDriftDetectedEventData.Serialization.cs
index 6e567f69cca0..89dd7cf816ab 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesDatasetDriftDetectedEventData.Serialization.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesDatasetDriftDetectedEventData.Serialization.cs
@@ -34,31 +34,16 @@ protected virtual void JsonModelWriteCore(Utf8JsonWriter writer, ModelReaderWrit
                 throw new FormatException($"The model {nameof(MachineLearningServicesDatasetDriftDetectedEventData)} does not support writing '{format}' format.");
             }
 
-            if (Optional.IsDefined(DataDriftId))
-            {
-                writer.WritePropertyName("dataDriftId"u8);
-                writer.WriteStringValue(DataDriftId);
-            }
-            if (Optional.IsDefined(DataDriftName))
-            {
-                writer.WritePropertyName("dataDriftName"u8);
-                writer.WriteStringValue(DataDriftName);
-            }
-            if (Optional.IsDefined(RunId))
-            {
-                writer.WritePropertyName("runId"u8);
-                writer.WriteStringValue(RunId);
-            }
-            if (Optional.IsDefined(BaseDatasetId))
-            {
-                writer.WritePropertyName("baseDatasetId"u8);
-                writer.WriteStringValue(BaseDatasetId);
-            }
-            if (Optional.IsDefined(TargetDatasetId))
-            {
-                writer.WritePropertyName("targetDatasetId"u8);
-                writer.WriteStringValue(TargetDatasetId);
-            }
+            writer.WritePropertyName("dataDriftId"u8);
+            writer.WriteStringValue(DataDriftId);
+            writer.WritePropertyName("dataDriftName"u8);
+            writer.WriteStringValue(DataDriftName);
+            writer.WritePropertyName("runId"u8);
+            writer.WriteStringValue(RunId);
+            writer.WritePropertyName("baseDatasetId"u8);
+            writer.WriteStringValue(BaseDatasetId);
+            writer.WritePropertyName("targetDatasetId"u8);
+            writer.WriteStringValue(TargetDatasetId);
             if (Optional.IsDefined(DriftCoefficient))
             {
                 writer.WritePropertyName("driftCoefficient"u8);
@@ -66,13 +51,27 @@ protected virtual void JsonModelWriteCore(Utf8JsonWriter writer, ModelReaderWrit
             }
             if (Optional.IsDefined(StartTime))
             {
-                writer.WritePropertyName("startTime"u8);
-                writer.WriteStringValue(StartTime.Value, "O");
+                if (StartTime != null)
+                {
+                    writer.WritePropertyName("startTime"u8);
+                    writer.WriteStringValue(StartTime.Value, "O");
+                }
+                else
+                {
+                    writer.WriteNull("startTime");
+                }
             }
             if (Optional.IsDefined(EndTime))
             {
-                writer.WritePropertyName("endTime"u8);
-                writer.WriteStringValue(EndTime.Value, "O");
+                if (EndTime != null)
+                {
+                    writer.WritePropertyName("endTime"u8);
+                    writer.WriteStringValue(EndTime.Value, "O");
+                }
+                else
+                {
+                    writer.WriteNull("endTime");
+                }
             }
             if (options.Format != "W" && _serializedAdditionalRawData != null)
             {
@@ -161,6 +160,7 @@ internal static MachineLearningServicesDatasetDriftDetectedEventData Deserialize
                 {
                     if (property.Value.ValueKind == JsonValueKind.Null)
                     {
+                        startTime = null;
                         continue;
                     }
                     startTime = property.Value.GetDateTimeOffset("O");
@@ -170,6 +170,7 @@ internal static MachineLearningServicesDatasetDriftDetectedEventData Deserialize
                 {
                     if (property.Value.ValueKind == JsonValueKind.Null)
                     {
+                        endTime = null;
                         continue;
                     }
                     endTime = property.Value.GetDateTimeOffset("O");
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesDatasetDriftDetectedEventData.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesDatasetDriftDetectedEventData.cs
index f86f30e006be..66d7e5943085 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesDatasetDriftDetectedEventData.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesDatasetDriftDetectedEventData.cs
@@ -46,8 +46,25 @@ public partial class MachineLearningServicesDatasetDriftDetectedEventData
         private IDictionary<string, BinaryData> _serializedAdditionalRawData;
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesDatasetDriftDetectedEventData"/>. </summary>
-        internal MachineLearningServicesDatasetDriftDetectedEventData()
+        /// <param name="dataDriftId"> The ID of the data drift monitor that triggered the event. </param>
+        /// <param name="dataDriftName"> The name of the data drift monitor that triggered the event. </param>
+        /// <param name="runId"> The ID of the Run that detected data drift. </param>
+        /// <param name="baseDatasetId"> The ID of the base Dataset used to detect drift. </param>
+        /// <param name="targetDatasetId"> The ID of the target Dataset used to detect drift. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="dataDriftId"/>, <paramref name="dataDriftName"/>, <paramref name="runId"/>, <paramref name="baseDatasetId"/> or <paramref name="targetDatasetId"/> is null. </exception>
+        internal MachineLearningServicesDatasetDriftDetectedEventData(string dataDriftId, string dataDriftName, string runId, string baseDatasetId, string targetDatasetId)
         {
+            Argument.AssertNotNull(dataDriftId, nameof(dataDriftId));
+            Argument.AssertNotNull(dataDriftName, nameof(dataDriftName));
+            Argument.AssertNotNull(runId, nameof(runId));
+            Argument.AssertNotNull(baseDatasetId, nameof(baseDatasetId));
+            Argument.AssertNotNull(targetDatasetId, nameof(targetDatasetId));
+
+            DataDriftId = dataDriftId;
+            DataDriftName = dataDriftName;
+            RunId = runId;
+            BaseDatasetId = baseDatasetId;
+            TargetDatasetId = targetDatasetId;
         }
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesDatasetDriftDetectedEventData"/>. </summary>
@@ -73,6 +90,11 @@ internal MachineLearningServicesDatasetDriftDetectedEventData(string dataDriftId
             _serializedAdditionalRawData = serializedAdditionalRawData;
         }
 
+        /// <summary> Initializes a new instance of <see cref="MachineLearningServicesDatasetDriftDetectedEventData"/> for deserialization. </summary>
+        internal MachineLearningServicesDatasetDriftDetectedEventData()
+        {
+        }
+
         /// <summary> The ID of the data drift monitor that triggered the event. </summary>
         public string DataDriftId { get; }
         /// <summary> The name of the data drift monitor that triggered the event. </summary>
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelDeployedEventData.Serialization.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelDeployedEventData.Serialization.cs
index 508c46bcc98e..93fdddf56cff 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelDeployedEventData.Serialization.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelDeployedEventData.Serialization.cs
@@ -34,61 +34,58 @@ protected virtual void JsonModelWriteCore(Utf8JsonWriter writer, ModelReaderWrit
                 throw new FormatException($"The model {nameof(MachineLearningServicesModelDeployedEventData)} does not support writing '{format}' format.");
             }
 
-            if (Optional.IsDefined(ServiceName))
+            writer.WritePropertyName("serviceName"u8);
+            writer.WriteStringValue(ServiceName);
+            writer.WritePropertyName("serviceComputeType"u8);
+            writer.WriteStringValue(ServiceComputeType);
+            writer.WritePropertyName("modelIds"u8);
+            writer.WriteStringValue(ModelIds);
+            if (Optional.IsCollectionDefined(ServiceTags))
             {
-                writer.WritePropertyName("serviceName"u8);
-                writer.WriteStringValue(ServiceName);
-            }
-            if (Optional.IsDefined(ServiceComputeType))
-            {
-                writer.WritePropertyName("serviceComputeType"u8);
-                writer.WriteStringValue(ServiceComputeType);
-            }
-            if (Optional.IsDefined(ModelIds))
-            {
-                writer.WritePropertyName("modelIds"u8);
-                writer.WriteStringValue(ModelIds);
-            }
-            writer.WritePropertyName("serviceTags"u8);
-            writer.WriteStartObject();
-            foreach (var item in ServiceTags)
-            {
-                writer.WritePropertyName(item.Key);
-                if (item.Value == null)
+                writer.WritePropertyName("serviceTags"u8);
+                writer.WriteStartObject();
+                foreach (var item in ServiceTags)
                 {
-                    writer.WriteNullValue();
-                    continue;
-                }
+                    writer.WritePropertyName(item.Key);
+                    if (item.Value == null)
+                    {
+                        writer.WriteNullValue();
+                        continue;
+                    }
 #if NET6_0_OR_GREATER
 				writer.WriteRawValue(item.Value);
 #else
-                using (JsonDocument document = JsonDocument.Parse(item.Value))
-                {
-                    JsonSerializer.Serialize(writer, document.RootElement);
-                }
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
 #endif
+                }
+                writer.WriteEndObject();
             }
-            writer.WriteEndObject();
-            writer.WritePropertyName("serviceProperties"u8);
-            writer.WriteStartObject();
-            foreach (var item in ServiceProperties)
+            if (Optional.IsCollectionDefined(ServiceProperties))
             {
-                writer.WritePropertyName(item.Key);
-                if (item.Value == null)
+                writer.WritePropertyName("serviceProperties"u8);
+                writer.WriteStartObject();
+                foreach (var item in ServiceProperties)
                 {
-                    writer.WriteNullValue();
-                    continue;
-                }
+                    writer.WritePropertyName(item.Key);
+                    if (item.Value == null)
+                    {
+                        writer.WriteNullValue();
+                        continue;
+                    }
 #if NET6_0_OR_GREATER
 				writer.WriteRawValue(item.Value);
 #else
-                using (JsonDocument document = JsonDocument.Parse(item.Value))
-                {
-                    JsonSerializer.Serialize(writer, document.RootElement);
-                }
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
 #endif
+                }
+                writer.WriteEndObject();
             }
-            writer.WriteEndObject();
             if (options.Format != "W" && _serializedAdditionalRawData != null)
             {
                 foreach (var item in _serializedAdditionalRawData)
@@ -152,6 +149,10 @@ internal static MachineLearningServicesModelDeployedEventData DeserializeMachine
                 }
                 if (property.NameEquals("serviceTags"u8))
                 {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        continue;
+                    }
                     Dictionary<string, BinaryData> dictionary = new Dictionary<string, BinaryData>();
                     foreach (var property0 in property.Value.EnumerateObject())
                     {
@@ -169,6 +170,10 @@ internal static MachineLearningServicesModelDeployedEventData DeserializeMachine
                 }
                 if (property.NameEquals("serviceProperties"u8))
                 {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        continue;
+                    }
                     Dictionary<string, BinaryData> dictionary = new Dictionary<string, BinaryData>();
                     foreach (var property0 in property.Value.EnumerateObject())
                     {
@@ -194,8 +199,8 @@ internal static MachineLearningServicesModelDeployedEventData DeserializeMachine
                 serviceName,
                 serviceComputeType,
                 modelIds,
-                serviceTags,
-                serviceProperties,
+                serviceTags ?? new ChangeTrackingDictionary<string, BinaryData>(),
+                serviceProperties ?? new ChangeTrackingDictionary<string, BinaryData>(),
                 serializedAdditionalRawData);
         }
 
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelDeployedEventData.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelDeployedEventData.cs
index 8d759992c57d..86cce0670b04 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelDeployedEventData.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelDeployedEventData.cs
@@ -46,16 +46,21 @@ public partial class MachineLearningServicesModelDeployedEventData
         private IDictionary<string, BinaryData> _serializedAdditionalRawData;
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesModelDeployedEventData"/>. </summary>
-        /// <param name="serviceTags"> The tags of the deployed service. </param>
-        /// <param name="serviceProperties"> The properties of the deployed service. </param>
-        /// <exception cref="ArgumentNullException"> <paramref name="serviceTags"/> or <paramref name="serviceProperties"/> is null. </exception>
-        internal MachineLearningServicesModelDeployedEventData(IReadOnlyDictionary<string, BinaryData> serviceTags, IReadOnlyDictionary<string, BinaryData> serviceProperties)
+        /// <param name="serviceName"> The name of the deployed service. </param>
+        /// <param name="serviceComputeType"> The compute type (e.g. ACI, AKS) of the deployed service. </param>
+        /// <param name="modelIds"> A common separated list of model IDs. The IDs of the models deployed in the service. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="serviceName"/>, <paramref name="serviceComputeType"/> or <paramref name="modelIds"/> is null. </exception>
+        internal MachineLearningServicesModelDeployedEventData(string serviceName, string serviceComputeType, string modelIds)
         {
-            Argument.AssertNotNull(serviceTags, nameof(serviceTags));
-            Argument.AssertNotNull(serviceProperties, nameof(serviceProperties));
+            Argument.AssertNotNull(serviceName, nameof(serviceName));
+            Argument.AssertNotNull(serviceComputeType, nameof(serviceComputeType));
+            Argument.AssertNotNull(modelIds, nameof(modelIds));
 
-            ServiceTags = serviceTags;
-            ServiceProperties = serviceProperties;
+            ServiceName = serviceName;
+            ServiceComputeType = serviceComputeType;
+            ModelIds = modelIds;
+            ServiceTags = new ChangeTrackingDictionary<string, BinaryData>();
+            ServiceProperties = new ChangeTrackingDictionary<string, BinaryData>();
         }
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesModelDeployedEventData"/>. </summary>
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelRegisteredEventData.Serialization.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelRegisteredEventData.Serialization.cs
index 8c623627b80b..73cae72cd20b 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelRegisteredEventData.Serialization.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelRegisteredEventData.Serialization.cs
@@ -34,56 +34,56 @@ protected virtual void JsonModelWriteCore(Utf8JsonWriter writer, ModelReaderWrit
                 throw new FormatException($"The model {nameof(MachineLearningServicesModelRegisteredEventData)} does not support writing '{format}' format.");
             }
 
-            if (Optional.IsDefined(ModelName))
+            writer.WritePropertyName("modelName"u8);
+            writer.WriteStringValue(ModelName);
+            writer.WritePropertyName("modelVersion"u8);
+            writer.WriteStringValue(ModelVersion);
+            if (Optional.IsCollectionDefined(ModelTags))
             {
-                writer.WritePropertyName("modelName"u8);
-                writer.WriteStringValue(ModelName);
-            }
-            if (Optional.IsDefined(ModelVersion))
-            {
-                writer.WritePropertyName("modelVersion"u8);
-                writer.WriteStringValue(ModelVersion);
-            }
-            writer.WritePropertyName("modelTags"u8);
-            writer.WriteStartObject();
-            foreach (var item in ModelTags)
-            {
-                writer.WritePropertyName(item.Key);
-                if (item.Value == null)
+                writer.WritePropertyName("modelTags"u8);
+                writer.WriteStartObject();
+                foreach (var item in ModelTags)
                 {
-                    writer.WriteNullValue();
-                    continue;
-                }
+                    writer.WritePropertyName(item.Key);
+                    if (item.Value == null)
+                    {
+                        writer.WriteNullValue();
+                        continue;
+                    }
 #if NET6_0_OR_GREATER
 				writer.WriteRawValue(item.Value);
 #else
-                using (JsonDocument document = JsonDocument.Parse(item.Value))
-                {
-                    JsonSerializer.Serialize(writer, document.RootElement);
-                }
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
 #endif
+                }
+                writer.WriteEndObject();
             }
-            writer.WriteEndObject();
-            writer.WritePropertyName("modelProperties"u8);
-            writer.WriteStartObject();
-            foreach (var item in ModelProperties)
+            if (Optional.IsCollectionDefined(ModelProperties))
             {
-                writer.WritePropertyName(item.Key);
-                if (item.Value == null)
+                writer.WritePropertyName("modelProperties"u8);
+                writer.WriteStartObject();
+                foreach (var item in ModelProperties)
                 {
-                    writer.WriteNullValue();
-                    continue;
-                }
+                    writer.WritePropertyName(item.Key);
+                    if (item.Value == null)
+                    {
+                        writer.WriteNullValue();
+                        continue;
+                    }
 #if NET6_0_OR_GREATER
 				writer.WriteRawValue(item.Value);
 #else
-                using (JsonDocument document = JsonDocument.Parse(item.Value))
-                {
-                    JsonSerializer.Serialize(writer, document.RootElement);
-                }
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
 #endif
+                }
+                writer.WriteEndObject();
             }
-            writer.WriteEndObject();
             if (options.Format != "W" && _serializedAdditionalRawData != null)
             {
                 foreach (var item in _serializedAdditionalRawData)
@@ -141,6 +141,10 @@ internal static MachineLearningServicesModelRegisteredEventData DeserializeMachi
                 }
                 if (property.NameEquals("modelTags"u8))
                 {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        continue;
+                    }
                     Dictionary<string, BinaryData> dictionary = new Dictionary<string, BinaryData>();
                     foreach (var property0 in property.Value.EnumerateObject())
                     {
@@ -158,6 +162,10 @@ internal static MachineLearningServicesModelRegisteredEventData DeserializeMachi
                 }
                 if (property.NameEquals("modelProperties"u8))
                 {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        continue;
+                    }
                     Dictionary<string, BinaryData> dictionary = new Dictionary<string, BinaryData>();
                     foreach (var property0 in property.Value.EnumerateObject())
                     {
@@ -179,7 +187,7 @@ internal static MachineLearningServicesModelRegisteredEventData DeserializeMachi
                 }
             }
             serializedAdditionalRawData = rawDataDictionary;
-            return new MachineLearningServicesModelRegisteredEventData(modelName, modelVersion, modelTags, modelProperties, serializedAdditionalRawData);
+            return new MachineLearningServicesModelRegisteredEventData(modelName, modelVersion, modelTags ?? new ChangeTrackingDictionary<string, BinaryData>(), modelProperties ?? new ChangeTrackingDictionary<string, BinaryData>(), serializedAdditionalRawData);
         }
 
         BinaryData IPersistableModel<MachineLearningServicesModelRegisteredEventData>.Write(ModelReaderWriterOptions options)
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelRegisteredEventData.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelRegisteredEventData.cs
index 66af5a595773..e844c536e50b 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelRegisteredEventData.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesModelRegisteredEventData.cs
@@ -46,16 +46,18 @@ public partial class MachineLearningServicesModelRegisteredEventData
         private IDictionary<string, BinaryData> _serializedAdditionalRawData;
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesModelRegisteredEventData"/>. </summary>
-        /// <param name="modelTags"> The tags of the model that was registered. </param>
-        /// <param name="modelProperties"> The properties of the model that was registered. </param>
-        /// <exception cref="ArgumentNullException"> <paramref name="modelTags"/> or <paramref name="modelProperties"/> is null. </exception>
-        internal MachineLearningServicesModelRegisteredEventData(IReadOnlyDictionary<string, BinaryData> modelTags, IReadOnlyDictionary<string, BinaryData> modelProperties)
+        /// <param name="modelName"> The name of the model that was registered. </param>
+        /// <param name="modelVersion"> The version of the model that was registered. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="modelName"/> or <paramref name="modelVersion"/> is null. </exception>
+        internal MachineLearningServicesModelRegisteredEventData(string modelName, string modelVersion)
         {
-            Argument.AssertNotNull(modelTags, nameof(modelTags));
-            Argument.AssertNotNull(modelProperties, nameof(modelProperties));
+            Argument.AssertNotNull(modelName, nameof(modelName));
+            Argument.AssertNotNull(modelVersion, nameof(modelVersion));
 
-            ModelTags = modelTags;
-            ModelProperties = modelProperties;
+            ModelName = modelName;
+            ModelVersion = modelVersion;
+            ModelTags = new ChangeTrackingDictionary<string, BinaryData>();
+            ModelProperties = new ChangeTrackingDictionary<string, BinaryData>();
         }
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesModelRegisteredEventData"/>. </summary>
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunCompletedEventData.Serialization.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunCompletedEventData.Serialization.cs
index afd9a764a504..38473db4367e 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunCompletedEventData.Serialization.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunCompletedEventData.Serialization.cs
@@ -34,66 +34,60 @@ protected virtual void JsonModelWriteCore(Utf8JsonWriter writer, ModelReaderWrit
                 throw new FormatException($"The model {nameof(MachineLearningServicesRunCompletedEventData)} does not support writing '{format}' format.");
             }
 
-            if (Optional.IsDefined(ExperimentId))
+            writer.WritePropertyName("experimentId"u8);
+            writer.WriteStringValue(ExperimentId);
+            writer.WritePropertyName("experimentName"u8);
+            writer.WriteStringValue(ExperimentName);
+            writer.WritePropertyName("runId"u8);
+            writer.WriteStringValue(RunId);
+            writer.WritePropertyName("runType"u8);
+            writer.WriteStringValue(RunType);
+            if (Optional.IsCollectionDefined(RunTags))
             {
-                writer.WritePropertyName("experimentId"u8);
-                writer.WriteStringValue(ExperimentId);
-            }
-            if (Optional.IsDefined(ExperimentName))
-            {
-                writer.WritePropertyName("experimentName"u8);
-                writer.WriteStringValue(ExperimentName);
-            }
-            if (Optional.IsDefined(RunId))
-            {
-                writer.WritePropertyName("runId"u8);
-                writer.WriteStringValue(RunId);
-            }
-            if (Optional.IsDefined(RunType))
-            {
-                writer.WritePropertyName("runType"u8);
-                writer.WriteStringValue(RunType);
-            }
-            writer.WritePropertyName("runTags"u8);
-            writer.WriteStartObject();
-            foreach (var item in RunTags)
-            {
-                writer.WritePropertyName(item.Key);
-                if (item.Value == null)
+                writer.WritePropertyName("runTags"u8);
+                writer.WriteStartObject();
+                foreach (var item in RunTags)
                 {
-                    writer.WriteNullValue();
-                    continue;
-                }
+                    writer.WritePropertyName(item.Key);
+                    if (item.Value == null)
+                    {
+                        writer.WriteNullValue();
+                        continue;
+                    }
 #if NET6_0_OR_GREATER
 				writer.WriteRawValue(item.Value);
 #else
-                using (JsonDocument document = JsonDocument.Parse(item.Value))
-                {
-                    JsonSerializer.Serialize(writer, document.RootElement);
-                }
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
 #endif
+                }
+                writer.WriteEndObject();
             }
-            writer.WriteEndObject();
-            writer.WritePropertyName("runProperties"u8);
-            writer.WriteStartObject();
-            foreach (var item in RunProperties)
+            if (Optional.IsCollectionDefined(RunProperties))
             {
-                writer.WritePropertyName(item.Key);
-                if (item.Value == null)
+                writer.WritePropertyName("runProperties"u8);
+                writer.WriteStartObject();
+                foreach (var item in RunProperties)
                 {
-                    writer.WriteNullValue();
-                    continue;
-                }
+                    writer.WritePropertyName(item.Key);
+                    if (item.Value == null)
+                    {
+                        writer.WriteNullValue();
+                        continue;
+                    }
 #if NET6_0_OR_GREATER
 				writer.WriteRawValue(item.Value);
 #else
-                using (JsonDocument document = JsonDocument.Parse(item.Value))
-                {
-                    JsonSerializer.Serialize(writer, document.RootElement);
-                }
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
 #endif
+                }
+                writer.WriteEndObject();
             }
-            writer.WriteEndObject();
             if (options.Format != "W" && _serializedAdditionalRawData != null)
             {
                 foreach (var item in _serializedAdditionalRawData)
@@ -163,6 +157,10 @@ internal static MachineLearningServicesRunCompletedEventData DeserializeMachineL
                 }
                 if (property.NameEquals("runTags"u8))
                 {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        continue;
+                    }
                     Dictionary<string, BinaryData> dictionary = new Dictionary<string, BinaryData>();
                     foreach (var property0 in property.Value.EnumerateObject())
                     {
@@ -180,6 +178,10 @@ internal static MachineLearningServicesRunCompletedEventData DeserializeMachineL
                 }
                 if (property.NameEquals("runProperties"u8))
                 {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        continue;
+                    }
                     Dictionary<string, BinaryData> dictionary = new Dictionary<string, BinaryData>();
                     foreach (var property0 in property.Value.EnumerateObject())
                     {
@@ -206,8 +208,8 @@ internal static MachineLearningServicesRunCompletedEventData DeserializeMachineL
                 experimentName,
                 runId,
                 runType,
-                runTags,
-                runProperties,
+                runTags ?? new ChangeTrackingDictionary<string, BinaryData>(),
+                runProperties ?? new ChangeTrackingDictionary<string, BinaryData>(),
                 serializedAdditionalRawData);
         }
 
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunCompletedEventData.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunCompletedEventData.cs
index e8c1fb9d4264..bbfe86bdb3e6 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunCompletedEventData.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunCompletedEventData.cs
@@ -46,16 +46,24 @@ public partial class MachineLearningServicesRunCompletedEventData
         private IDictionary<string, BinaryData> _serializedAdditionalRawData;
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesRunCompletedEventData"/>. </summary>
-        /// <param name="runTags"> The tags of the completed Run. </param>
-        /// <param name="runProperties"> The properties of the completed Run. </param>
-        /// <exception cref="ArgumentNullException"> <paramref name="runTags"/> or <paramref name="runProperties"/> is null. </exception>
-        internal MachineLearningServicesRunCompletedEventData(IReadOnlyDictionary<string, BinaryData> runTags, IReadOnlyDictionary<string, BinaryData> runProperties)
+        /// <param name="experimentId"> The ID of the experiment that the run belongs to. </param>
+        /// <param name="experimentName"> The name of the experiment that the run belongs to. </param>
+        /// <param name="runId"> The ID of the Run that was completed. </param>
+        /// <param name="runType"> The Run Type of the completed Run. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="experimentId"/>, <paramref name="experimentName"/>, <paramref name="runId"/> or <paramref name="runType"/> is null. </exception>
+        internal MachineLearningServicesRunCompletedEventData(string experimentId, string experimentName, string runId, string runType)
         {
-            Argument.AssertNotNull(runTags, nameof(runTags));
-            Argument.AssertNotNull(runProperties, nameof(runProperties));
+            Argument.AssertNotNull(experimentId, nameof(experimentId));
+            Argument.AssertNotNull(experimentName, nameof(experimentName));
+            Argument.AssertNotNull(runId, nameof(runId));
+            Argument.AssertNotNull(runType, nameof(runType));
 
-            RunTags = runTags;
-            RunProperties = runProperties;
+            ExperimentId = experimentId;
+            ExperimentName = experimentName;
+            RunId = runId;
+            RunType = runType;
+            RunTags = new ChangeTrackingDictionary<string, BinaryData>();
+            RunProperties = new ChangeTrackingDictionary<string, BinaryData>();
         }
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesRunCompletedEventData"/>. </summary>
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunStatusChangedEventData.Serialization.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunStatusChangedEventData.Serialization.cs
index bf9acb0dc685..8e374d66b263 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunStatusChangedEventData.Serialization.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunStatusChangedEventData.Serialization.cs
@@ -34,71 +34,62 @@ protected virtual void JsonModelWriteCore(Utf8JsonWriter writer, ModelReaderWrit
                 throw new FormatException($"The model {nameof(MachineLearningServicesRunStatusChangedEventData)} does not support writing '{format}' format.");
             }
 
-            if (Optional.IsDefined(ExperimentId))
+            writer.WritePropertyName("experimentId"u8);
+            writer.WriteStringValue(ExperimentId);
+            writer.WritePropertyName("experimentName"u8);
+            writer.WriteStringValue(ExperimentName);
+            writer.WritePropertyName("runId"u8);
+            writer.WriteStringValue(RunId);
+            writer.WritePropertyName("runType"u8);
+            writer.WriteStringValue(RunType);
+            if (Optional.IsCollectionDefined(RunTags))
             {
-                writer.WritePropertyName("experimentId"u8);
-                writer.WriteStringValue(ExperimentId);
-            }
-            if (Optional.IsDefined(ExperimentName))
-            {
-                writer.WritePropertyName("experimentName"u8);
-                writer.WriteStringValue(ExperimentName);
-            }
-            if (Optional.IsDefined(RunId))
-            {
-                writer.WritePropertyName("runId"u8);
-                writer.WriteStringValue(RunId);
-            }
-            if (Optional.IsDefined(RunType))
-            {
-                writer.WritePropertyName("runType"u8);
-                writer.WriteStringValue(RunType);
-            }
-            writer.WritePropertyName("runTags"u8);
-            writer.WriteStartObject();
-            foreach (var item in RunTags)
-            {
-                writer.WritePropertyName(item.Key);
-                if (item.Value == null)
+                writer.WritePropertyName("runTags"u8);
+                writer.WriteStartObject();
+                foreach (var item in RunTags)
                 {
-                    writer.WriteNullValue();
-                    continue;
-                }
+                    writer.WritePropertyName(item.Key);
+                    if (item.Value == null)
+                    {
+                        writer.WriteNullValue();
+                        continue;
+                    }
 #if NET6_0_OR_GREATER
 				writer.WriteRawValue(item.Value);
 #else
-                using (JsonDocument document = JsonDocument.Parse(item.Value))
-                {
-                    JsonSerializer.Serialize(writer, document.RootElement);
-                }
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
 #endif
+                }
+                writer.WriteEndObject();
             }
-            writer.WriteEndObject();
-            writer.WritePropertyName("runProperties"u8);
-            writer.WriteStartObject();
-            foreach (var item in RunProperties)
+            if (Optional.IsCollectionDefined(RunProperties))
             {
-                writer.WritePropertyName(item.Key);
-                if (item.Value == null)
+                writer.WritePropertyName("runProperties"u8);
+                writer.WriteStartObject();
+                foreach (var item in RunProperties)
                 {
-                    writer.WriteNullValue();
-                    continue;
-                }
+                    writer.WritePropertyName(item.Key);
+                    if (item.Value == null)
+                    {
+                        writer.WriteNullValue();
+                        continue;
+                    }
 #if NET6_0_OR_GREATER
 				writer.WriteRawValue(item.Value);
 #else
-                using (JsonDocument document = JsonDocument.Parse(item.Value))
-                {
-                    JsonSerializer.Serialize(writer, document.RootElement);
-                }
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
 #endif
+                }
+                writer.WriteEndObject();
             }
-            writer.WriteEndObject();
-            if (Optional.IsDefined(RunStatus))
-            {
-                writer.WritePropertyName("runStatus"u8);
-                writer.WriteStringValue(RunStatus);
-            }
+            writer.WritePropertyName("runStatus"u8);
+            writer.WriteStringValue(RunStatus);
             if (options.Format != "W" && _serializedAdditionalRawData != null)
             {
                 foreach (var item in _serializedAdditionalRawData)
@@ -169,6 +160,10 @@ internal static MachineLearningServicesRunStatusChangedEventData DeserializeMach
                 }
                 if (property.NameEquals("runTags"u8))
                 {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        continue;
+                    }
                     Dictionary<string, BinaryData> dictionary = new Dictionary<string, BinaryData>();
                     foreach (var property0 in property.Value.EnumerateObject())
                     {
@@ -186,6 +181,10 @@ internal static MachineLearningServicesRunStatusChangedEventData DeserializeMach
                 }
                 if (property.NameEquals("runProperties"u8))
                 {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        continue;
+                    }
                     Dictionary<string, BinaryData> dictionary = new Dictionary<string, BinaryData>();
                     foreach (var property0 in property.Value.EnumerateObject())
                     {
@@ -217,8 +216,8 @@ internal static MachineLearningServicesRunStatusChangedEventData DeserializeMach
                 experimentName,
                 runId,
                 runType,
-                runTags,
-                runProperties,
+                runTags ?? new ChangeTrackingDictionary<string, BinaryData>(),
+                runProperties ?? new ChangeTrackingDictionary<string, BinaryData>(),
                 runStatus,
                 serializedAdditionalRawData);
         }
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunStatusChangedEventData.cs b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunStatusChangedEventData.cs
index 8af67e302b82..c7c35d6ed14e 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunStatusChangedEventData.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/src/Generated/MachineLearningServicesRunStatusChangedEventData.cs
@@ -46,16 +46,27 @@ public partial class MachineLearningServicesRunStatusChangedEventData
         private IDictionary<string, BinaryData> _serializedAdditionalRawData;
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesRunStatusChangedEventData"/>. </summary>
-        /// <param name="runTags"> The tags of the Machine Learning Run. </param>
-        /// <param name="runProperties"> The properties of the Machine Learning Run. </param>
-        /// <exception cref="ArgumentNullException"> <paramref name="runTags"/> or <paramref name="runProperties"/> is null. </exception>
-        internal MachineLearningServicesRunStatusChangedEventData(IReadOnlyDictionary<string, BinaryData> runTags, IReadOnlyDictionary<string, BinaryData> runProperties)
+        /// <param name="experimentId"> The ID of the experiment that the Machine Learning Run belongs to. </param>
+        /// <param name="experimentName"> The name of the experiment that the Machine Learning Run belongs to. </param>
+        /// <param name="runId"> The ID of the Machine Learning Run. </param>
+        /// <param name="runType"> The Run Type of the Machine Learning Run. </param>
+        /// <param name="runStatus"> The status of the Machine Learning Run. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="experimentId"/>, <paramref name="experimentName"/>, <paramref name="runId"/>, <paramref name="runType"/> or <paramref name="runStatus"/> is null. </exception>
+        internal MachineLearningServicesRunStatusChangedEventData(string experimentId, string experimentName, string runId, string runType, string runStatus)
         {
-            Argument.AssertNotNull(runTags, nameof(runTags));
-            Argument.AssertNotNull(runProperties, nameof(runProperties));
+            Argument.AssertNotNull(experimentId, nameof(experimentId));
+            Argument.AssertNotNull(experimentName, nameof(experimentName));
+            Argument.AssertNotNull(runId, nameof(runId));
+            Argument.AssertNotNull(runType, nameof(runType));
+            Argument.AssertNotNull(runStatus, nameof(runStatus));
 
-            RunTags = runTags;
-            RunProperties = runProperties;
+            ExperimentId = experimentId;
+            ExperimentName = experimentName;
+            RunId = runId;
+            RunType = runType;
+            RunTags = new ChangeTrackingDictionary<string, BinaryData>();
+            RunProperties = new ChangeTrackingDictionary<string, BinaryData>();
+            RunStatus = runStatus;
         }
 
         /// <summary> Initializes a new instance of <see cref="MachineLearningServicesRunStatusChangedEventData"/>. </summary>
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/tsp-location.yaml b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/tsp-location.yaml
index d1155a2c95e9..927b5ab26767 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/tsp-location.yaml
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid.SystemEvents/tsp-location.yaml
@@ -1,3 +1,4 @@
+directory: specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents
+commit: 224c26d59b44c950d736c0cc5c6b3a9305255e80
 repo: Azure/azure-rest-api-specs
-directory: "specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents"
-commit: 8af03db33a90581edffb8a32fea562f36b7c61a8
+additionalDirectories: