This might be helpful, if you have legacy XNA 4.0 projects and you want to be able to build them with Visual Studio 2019 Community.
I found this a guide on how to do it here:
After following this guide I needed to do additionally the following steps to be able to build XNA 4.0 projects which were suggested as a workaround by roy-t in the thread here:
1. Open a command prompt
cd C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\Tools\
4. Within VsDevCmd.bat
cd C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\15.0\Bin\
gacutil /i Microsoft.Build.Framework.dll
After that I am able to create new XNA 4.0 solutions and also to open and build existing ones.
Just wanted to share the solution