> Then C# came and said

It's worse than that. The WASM GC standards team was warned in advance that the proposal wouldn't work for .NET, and they moved forward with it anyway:

https://github.com/WebAssembly/gc/issues/77

They were also warned about Go (though I'm not sure if they ever actually consulted with golang devs):

https://github.com/WebAssembly/gc/issues/36

More links:

https://github.com/dotnet/runtime/issues/94420

https://github.com/golang/go/issues/63904