It seems like they do though, because

1. it's explicitly allowed

   Code or other content generated in whole or in part using AI tools can be contributed to Linux Foundation projects.

   and beyond that,

2. some numbers suggest it's highly likely that it's happening with no public concern or pushback from the kernel leadership.

I've also brought up these concerns on the mailing list, with apparently no response from the maintainers, even though Linus was CC'ed here by another kernel dev. Specifically, my suggestion to not allow AI code submissions resulted in no response.

I'm not saying I would be owed a response. But the implications of that seem pretty clear.