Document SDKAnalysisLevel expiry (#48112)

Author: gewarren

docs/core/project-sdk/msbuild-props.md

@@ -1445,7 +1445,7 @@ The following MSBuild properties are documented in this section:
 
 Introduced in .NET 9, the `SdkAnalysisLevel` property can be used to configure how *strict* SDK tooling is. It helps you manage SDK warning levels in situations where you might not be able to pin SDKs via *global.json* or other means. You can use this property to tell a newer SDK to behave as if it were an older SDK, with regards to a specific tool or feature, without having to install the older SDK.
 
-The allowed values of this property are SDK feature bands, for example, 8.0.100 and 8.0.400. The value defaults to the SDK feature band of the running SDK. For example, for SDK 9.0.102, the value would be 9.0.100. (For information about how the .NET SDK is versioned, see [How .NET is versioned](../versions/index.md).)
+The allowed values of this property are SDK feature bands, for example, 8.0.100 and 8.0.400. The value defaults to the SDK feature band of the running SDK. For example, for SDK 9.0.102, the value to use is 9.0.100. (For information about how the .NET SDK is versioned, see [How .NET is versioned](../versions/index.md).)
 
 ```xml
 <PropertyGroup>
@@ -1455,14 +1455,17 @@ The allowed values of this property are SDK feature bands, for example, 8.0.100
 
 For more information, see [SDK Analysis Level Property and Usage](https://github.com/dotnet/designs/blob/main/proposed/sdk-analysis-level.md).
 
-The following table summarizes the diagnostics affected by `SDKAnalysisLevel`.
+The following table summarizes the diagnostics and behaviors affected by `SDKAnalysisLevel`.
 
-| SDKAnalysisLevel | Diagnostic | Previous | Current |
-|------------------------|-----------|--------|-------|
-| 9.0.100 | Restore HTTP sources diagnostic | [NU1803](/nuget/reference/errors-and-warnings/nu1803) warning | [NU1302](/nuget/reference/errors-and-warnings/nu1302) error. |  
-| 10.0.100 | Restore package pruning, [PrunePackageReference](/nuget/consume-packages/package-references-in-project-files#prunepackagereference), enabled by default | N/A | Enabled for projects that target .NET 8+ or .NET Standard 2.0+ |
-| 10.0.100 | Restore resolver with lock files | Uses legacy dependency graph resolver (.NET 8 SDK and earlier) | Uses improved, [.NET 9 dependency graph resolver](/nuget/consume-packages/package-references-in-project-files#nuget-dependency-resolver) |
-| 10.0.100 | Restore behavior for PackageReference without a version | [NU1603](/nuget/reference/errors-and-warnings/nu1603) warning | [NU1015](/nuget/reference/errors-and-warnings/nu1015) error |
+| SDKAnalysisLevel | Description                     | Updated behavior |
+|------------------|---------------------------------|------------------|
+| 9.0.100          | Restore HTTP sources diagnostic | Emits [NU1302](/nuget/reference/errors-and-warnings/nu1302) error instead of [NU1803](/nuget/reference/errors-and-warnings/nu1803) warning. |
+| 10.0.100         | 'Restore' package pruning       | [PrunePackageReference](/nuget/consume-packages/package-references-in-project-files#prunepackagereference) is enabled by default for projects that target .NET 8+ or .NET Standard 2.0+. |
+| 10.0.100         | 'Restore' resolver with lock files | Uses improved, [.NET 9 dependency graph resolver](/nuget/consume-packages/package-references-in-project-files#nuget-dependency-resolver) instead of legacy dependency graph resolver (.NET 8 SDK and earlier). |
+| 10.0.100         | 'Restore' behavior for PackageReference without a version | Emits [NU1015](/nuget/reference/errors-and-warnings/nu1015) error instead of [NU1603](/nuget/reference/errors-and-warnings/nu1603) warning. |
+
+> [!NOTE]
+> The behavior enabled by the `SdkAnalysisLevel` value ages out (expires) after three major releases. For example, version 11.0.100 only respects values down to 8.0.100. In version 12.0.100, features that could, in previous versions, be disabled by setting an `SdkAnalysisLevel` value of 8.0.100 would no longer be disabled.
 
 ## Microsoft.Testing.Platform&ndash;related properties