I don't know what is meant by "there are plans to integrate WASM with the other GC's in the browser". Is the idea that the browser runs a GC for DOM elements that is separate from the JS VM GC? I wonder if they could follow a model like operating system resources (e.g., file handles) where the process is responsible for managing the resource lifetimes. This would make resource management trivial, and running (for example) Python on WASM would simply mean emitting WASM instructions instead of x86.

Of course, lots of other problems remain, for example, downloading an entire runtime or "putting Python on WASM isn't going to magically make it fast". But I don't think the GC should be a particularly large challenge.