Something still feels off if the formal proof can't be understood. I don't dispute its correctness, but there's a big jump from 4 color theorem, where at least mathematicians understood the program, to this, where GPT did the whole thing. Like if GPT ceased to exist, nobody would have a clue how to recreate the formalization. Or maybe there's a step in there that's a breakthrough to some other problem, but since it was generated, we'll never notice it.