That guy is stupid, the part of human nature containing dishonesty also houses "following the path of least resistance", which means that these people will simply contribute to another leading compiler without these rules.
So the real question is: what's LLVM policy?
Full text is linked below, but it is getting revised pretty regularly.
tl;dr: Requirement is that a human must be in the loop; the contributor must have reviewed the change by hand already; and is always accountable; the human must be able to answer questions about the change, such as strategy chosen, corner cases, etc. etc.
Even with this very permissive and well considered policy, they get a lot of slop submissions. Huge amounts of pure trash. And the debate continues about what to do about it.
Some are in favor of forbidding it simply because it would reduce the amount of slop they have to wade through, and the 10% good prs done with AI don't outweigh the 90% pure junk prs. Reviewer time is way too scarce.
But it is just as controversial there as it is over on lwn.
https://llvm.org/docs/AIToolPolicy.html