I think they meant it as "indistinguishable from a human contribution".

Here's to hoping LLVM will define it differently.

LLVM defined its AI policy several months ago: https://llvm.org/docs/AIToolPolicy.html

(There's already some consternation that it's too permissive.)

Reasonable policy. It's fine to make it less permissive on the basis of quality. It's the "AI, therefore slop" prejudice that's problematic.