IMHO, the "turbofish" syntax (popularized by Rust) is ugly and should not be used. The reasoning of syntax ambiguity is also a lame one because C# manages just fine without it. But to then say that:

> The above syntax is already valid JavaScript that users may rely on, so we cannot use this syntax as-is.

What users would be using said syntax? Why would one compare a function to a type? If we're making a backwards incompatible change, just say that `func < type` is a syntax error unless immediately followed by the rest of a call. IMO, in any spec committee, if a naysayer says that "someone may be using that syntax", they should be required to prove it. Prove that someone is comparing a function to be less than a type, and why they'd do such a thing.

Honestly, I don't see how this can be done in a backwards compatible way short of type annotations in comments. Just rip the bandaid off and have WHATWG say that TypeScript is a valid runtime and allow `<script src="..." type="typescript">`. Deno manages to have a TypeScript runtime just fine.