Nah its perfectly reasonable to worry, and honestly a lot of what I assert is just opinion.
LLMs are very good at playing utilitarian, "helper" roles, like a program. Parsing big blocks of text to flag things for humans, categorization, search, workflow automation; text models were doing this before we started calling them LLMs.
I honestly don't know the details, but getting LLMs to screen PRs sounds like wonderful automation to me. "Is this a vibecoded mess, and why?" "Does this conform to X standard?" Security issues. Raising flags before reviewing. I'd guess the kernel maintainers are using LLMs for "bulk prescreening," but maintainers are still going to look at every line of code with their eyeballs before it goes into the kernel. An analogy might me an LLM that flags issues for Wikpedia editors (spam, malicious edits, categorization, formatting nagging, citation requirements) to speed up "busywork," but ultimately every consequential action has to go through a human.
LLMs also great at generating boilerplate, refactoring a line, making a testing script; small, focused tasks. I bet the kernel devs will use it for that, and IMO that's harmless.
I just don't think they will allow vibecoded slop into the kernel. They've been draconian about code quality for decades, and they aren't going to change. And the way I see it, the LLM submission reviewing is fighting fire with fire.