Moreover, this is a breach of trust between the reviewer and the author. Our assumption when we review is that we're talking to a real person who wants to do their best work.

I think this is a really excellent point and gets at a general feeling I've had towards LLM-generated PR comments for a while now. I can understand the desire to use LLMs to generate changes (my company pushes AI super hard and it genuinely is a helpful tool in many cases), but to delegate discussion of those changes to an AI model feels extremely antisocial to me. I don't really like the idea of vibe-coding in general, and this practice really distills down everything I don't like about it with an added layer of deception.