It also assumes that people who are "good" at the standard code review process (which is tuned for reviewing code written by humans with some level of domain experience and thus finding human-looking mistakes) will be able to translate their skills perfectly to reviewing code written by AI. There have been plenty of examples where this review process was shown to be woefully insufficient for things outside of this scope (for instance, malicious patches like the bad patches scandal with Linux a few years ago or the xz backdoor were only discovered after the fact).

I haven't had to review too much AI code yet, but from what I've seen it tends to be the kind of code review that really requires you to think hard and so seems likely to lead to mistakes even with decent code reviewers. (I wouldn't say that I'm a brilliant code reviewer, but I have been doing open source maintenance full-time for around a decade at this point so I would say I have some experience with code reviews.)