Obfuscated javascript could still import a WebAssembly polyfill, if there really was any advantage in doing so: https://github.com/evanw/polywasm
Since WebAssembly instructions are much easier to reason about, you could probably auto-optimize away a lot of the obfuscation, like "this is a silly way to do X, so we can just do X directly".
Since WebAssembly instructions are much easier to reason about, you could probably auto-optimize away a lot of the obfuscation, like "this is a silly way to do X, so we can just do X directly".