doc(proguard): No inbound filters (#15543)

Author: jjbayer

docs/concepts/data-management/filtering/index.mdx

@@ -151,6 +151,12 @@ To use inbound data filters for error messages, keep the following in mind:
 
 To ensure you're adding the correct message to the inbound filter setting, check the JSON for an event in the issue. The filter by error message setting matches the data found in the "title" field near the end of the file.
 
+<Alert title="Note" level="warning">
+
+Matching on the deobfuscated `{exception.type}` is not supported for <PlatformLink to="/enhance-errors/proguard/">ProGuard</PlatformLink> events, because deobfuscation of class names happens after ingestion.
+
+</Alert>
+
 ### Releases
 
 To filter releases, keep the following in mind: