I think you're a little naive if you think this is because of gate-keeping by mathematicians rather than the essential complexity of mathematics. Mathematicians individually and as a group would love nothing more than a world which is capable of understanding their work more deeply.
In the exact same way that LLMs allow anyone to vibe code an app but do not replace real understanding of system design due to its essential complexity, non-mathematicians will quickly learn that asking an LLM to pump out advanced mathematical statements to you, even if they are correct (and even if you could verify them) does not constitute understanding, and that the human brain is the bottleneck either way.
It is only if the LLM is super-human at simplification and explaining that a difference will be noted. This would be excellent for mathematics but its not a foregone conclusion (and the argument of most mathematicians, such as Terence Tao, is that this distillation process is one of the key parts of doing mathematics, and that LLMs so far seem to be going in the opposite direction. I suspect its probably user error and leveraging the tools better will produce different outcomes, but mathematicians are only just starting the journey that software developers have been going through, so patience is needed).
Folks keep using the word "gate keeping" -- I never used that term nor implied intentional gate keeping. It's simply not caring if those outside the club understand -- there is no one guarding the door its just folks don't care if anyone finds it.
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.