I think every maintainer should be able to say how they want or don't want others to contribute. But i feel like it was always true that patches from the internet at large were largely more trouble then they were worth most of the time. The reason people accept them is not for the sake of the patch itself but because that is how you get new contributors who eventually become useful.
When you actually work alongside people and everyone builds a similar mental model of the codebase then communication between humans is far more effective than LLMs.
For random contributions then this doesn’t apply