Strategic NOTEs for hosted Blazor migrations (#20511)

aspnetcore/migration/31-to-50.md

@@ -68,6 +68,9 @@ For a Blazor WebAssembly project, including the *`Client`* project of a hosted B
     - <Project Sdk="Microsoft.NET.Sdk.Web">
     + <Project Sdk="Microsoft.NET.Sdk.BlazorWebAssembly">
     ```
+    
+    > [!NOTE]
+    > This update only applies to standalone Blazor WebAssembly projects and the *`Client`* projects of hosted Blazor solutions.
 
 1. Update the following properties:
 
@@ -176,6 +179,13 @@ For AAD B2C:
 +<PackageReference Include="Microsoft.Identity.Web.UI" Version="1.2.0" />
 ```
 
+> [!NOTE]
+> The SDK of the *`Server`* project in a hosted Blazor WebAssembly solution remains `Microsoft.NET.Sdk.Web`:
+>
+> ```xml
+> <Project Sdk="Microsoft.NET.Sdk.Web">
+> ```
+
 For more information, see:
 
 * <xref:blazor/security/webassembly/hosted-with-azure-active-directory>