I'm worried that Microsoft may decide to take down this project in the future. Since Github is owned by Microsoft, this is a trivial thing for them to do. So I suggest creating a mirror of this project to another site. Gitlab, BitBucket, & Sourceforge are some examples.

Done.

It's kinda unlikely. Even if they make up an excuse to take it down, the developer would still have the code locally and it's gonna be the CurseForge/Modrinth situation once again - Microsoft would just get more hate on itself and more people will know about the mod.

nontheless it's a good idea to have some sort of backups in case something like that happens