I haven't been exposed AI reviews in OSS but I like them for work. Quality of PR review feedback is the most revolutionary bit of AI I think. More so than automated coding. I guess one issue with the AI reviews in OSS is that your dialog (I assume) is public. You know the interaction is with a bot but you also sense it may be observed by humans.
If I get a review at work from a bot that is annoying, misunderstands, etc I just ignore their reviews, or tell the bot to leave me alone. The bot is there to help me, and if it doesn't - that's not my problem. There's also always a human reviewer. For any automated feedback for PR's I think there should be "manual review" requests. If you disagree and the bot can decide that there is real human effort involved, then just let real humans also make the effort to review.
This is the key idea: to spend the human effort from maintainers, where there has been human effort from contributors. The AI should be able to determine the amount of human effort in a contribution. The bot should be an aid to make sure the human maintainer effort is spent only where there is human contributor effort.
So i'm critical of LLMs even if you consent to their use (for ecological/political/cognitive reasons). But in that case at least it's your tool and your expectations. I'm not even sure the maintainers had a say in the random LLM interactions i had on their projects, but i certainly didn't consent.
If the maintainer wants a LLM to review my PRs, let the maintainer use a LLM. Don't make me deal with abrasive chatbots when you want to deal with abrasive chatbots. I don't want an LLM to pre-screen my work to decide if a human should review it; a human should decide if my contribution is worth it. Otherwise, that project is not worthy of my modest contribution.