Not to mention people who are still on the other side nominally in control but send LLM generated patches without declaring them as such.

Then you basically need to review any review from people that might be long term contributors but you don't know personally as new contributor patches, as the code is not from their head & you can't risk them properly reviewing it on their end.

To a degree its will always be a new contributor - an amnesiac LLM prompted to produce the patch with zero memory of any past PRs & lot of entropy in the mix.