Gatekeeping is a human universal. Even those who preach maximum inclusion do exclude plenty, of course there is always explanation why that doesn't count. If you try to run any community you quickly learn the importance of gatekeeping. Eternal September etc. See any site or fandom that gets mainstream etc. I don't think anyone has any duty to actively pull in as many as possible new people. Zen masters used to chase away students or make them sit on their doorstep for days and send them away anyway. Now, the west is essentially Christian and so the missionary impulse is real, but it doesn't work without the other stuff in the package.
Again with the gatekeeping. An AI generating a convoluted proof for some conjecture is not gatekeeping. It just does not care if you understand. It only cares enough that it can be verified -- usually using some other opaque proof tool like Lean.
AI is much less gatekeeping and much more welcoming for beginners than human experts are in general. It has infinite patience to break things down for your level of understanding. So AI has less gatekeeping which I like when I'm gatekept out of something otherwise. But I recognize the social function of gatekeeping and I don't see it as an inherent evil.