[paulddraper]

I think you know the poster is taking about programming languages, where the bulk of complexity lies.

[trusktr]

Yes, but WebAssembly operates at the boundary with JS, and that is not UTF-8. JS uses WTF-16 at runtime, and if WebAssembly did too then this would make interop between Wasm and JS a first-class feature with maximal performance and without security and data integrity issues.