Fix for #42882 (#43011)

Author: samwherever

docs/core/compatibility/9.0.md

@@ -34,7 +34,7 @@ If you're migrating an app to .NET 9, the breaking changes listed here might aff
 |------------------------------------------------------------------------------------------|---------------------|--------------------|
 | [Adding a ZipArchiveEntry with CompressionLevel sets ZIP central directory header general-purpose bit flags](core-libraries/9.0/compressionlevel-bits.md) | Behavioral change | Preview 5 |
 | [Altered UnsafeAccessor support for non-open generics](core-libraries/9.0/unsafeaccessor-generics.md) | Behavioral change   | Preview 6          |
-| [API obsoletions with custom diagnostic IDs](core-libraries/9.0/obsolete-apis-with-custom-diagnostics.md) | Source incompatible | Preview 16 |
+| [API obsoletions with custom diagnostic IDs](core-libraries/9.0/obsolete-apis-with-custom-diagnostics.md) | Source incompatible | (Multiple) |
 | [BigInteger maximum length](core-libraries/9.0/biginteger-limit.md) | Behavioral change | Preview 6  |
 | [BinaryReader.GetString() returns "/uFFFD" on malformed sequences](core-libraries/9.0/binaryreader.md) | Behavioral change | Preview 7  |
 | [Creating type of array of System.Void not allowed](core-libraries/9.0/type-instance.md) | Behavioral change   | Preview 1          |