Earlier quoted context omitted.
You can already do that from .NET itself. My question here is more along the lines of: "what Rust libs are out there that I might be interested in from .NET?"
What I think you missed in that statement is that the code is technically still Rust safe, so in theory it wouldn't just be unsafe .NET Code, it would be Rust safe code that happens to run on .NET with a speed up since its less managed. It's kind of genius, if I'm not misunderstanding.
If you do not want JITing, you can already "pre-compile" dotnet code, and you will achieve near-native performance in either case—far better performance than running Rust as IL, as the author indicated.
In my opinion, the use case for this is minuscule at best.