Not at all. It's much more efficient to implement a GC on x86 or ARM than it is on Wasm 1.0/2.0, because you control the stack layout, and you don't have an impenetrable security boundary with the JS runtime that your GC needs to interop with.
Not to mention the issue that bundling a GC implementation as part of your web page can be prohibitive in terms of download size.
Tbh I never understood nor cared why people would want to use a garbage collected language with WASM in browsers when there's already Javascript. One of the main points of WASM was to avoid GC overhead alltogether (thus the 'garbage-free' subset asm.js which then became WASM).
Not to mention the issue that bundling a GC implementation as part of your web page can be prohibitive in terms of download size.