Wouldn't the proof be attributed to the people who operated the AI? After all, it took more than writing a "prove the navier Stokes Clay problem" prompt.
Yes, but it took far less than using your meat brain to prove the Navier-Stokes Clay problem.
I assume that the mathematicians outside Anthropic were hoping to publish an actual human-understandable paper. That could be one way to draw line: you can use AI, but you must also have an intelligible explanation at the end.