Update rational for conditional MUX reference

Author: Arlodotexe

MultiTarget/PackageReferences/Uwp/Microsoft.UI.Xaml.props

@@ -8,7 +8,7 @@
 		</When>
 		<When Condition="'$(HasWinUI)' == 'true' AND '$(MultiTargetPlatformIdentifier)' == 'windows'" >
 			<ItemGroup>
-				<!-- This preview version breaks uap builds by referencing Microsoft.VCLibs.Desktop when it shouldn't -->
+				<!-- Prerelease version needed for TargetFramework support. Not needed by uap. -->
 				<PackageReference Include="Microsoft.UI.Xaml" Version="2.8.7-prerelease.241119001" />
 			</ItemGroup>
 		</When>