I will admit, I made this thread when pretty frustrated and upset about it. SystemD is so key to the security of many peoples' machines. I don't necessarily see having security reviews be a problem the same way that codegen and etc are. And I was wrong about the PR review vulnerability risk in that *for now* afaict the review bot is just performing read-only security review, is not taking auto-action on merging, which is the real risk.
So maybe I overreacted? But Poettering's comment reads the way that most comments I have read that have been drawn into AIgen code have gone, which is "you gotta admit that things are changing, these things are getting really good" and then opening the door to aigen contributions. Which I am very wary of...