So long as the wasm blob can be read as Rust by a third party.
If it's a one-way Rust source -> wasm transformation, even a Rust user might have a hard time following what wasm spits out.
Re:From Asm.js to WebAssembly
by AriaMinaei on Friday June 19, 2015 @06:21AM
(#9743883)
I agree that giving authors more freedom is a good thing, but as I argued, it also has serious downsides. But I think there are ways to keep the best of both worlds. I wrote a comment here with more detail: https://news.ycombinator.com/item?id=9743859
For example I may chose to write my code in Rust and that imposes a burden on you (assuming you know only Javascript), but it does not curtail your freedom. Not as convenient as before for you since you now need to learn Rust. I think the freedom has spread to the person who is creating the content (code). The general consumer does not care, but the tinkerer/hacker now needs to put in more effort to parse the creation.