My perception is different. I start from the axiom that AI is a massive compressed corpus of knowledge. That it can find solutions suggests to me that the solutions were already known, but simply lacked publicity. This is less about discovery and more about pattern-matching.
Why does being a compressed corpus of knowledge mean it can't discover things? What if it has knowledge of techniques to discover proofs?
It does and that's what's happening.
That axiom is clearly false. AI can interact with external systems, which means it is not just compressed knowledge - it has the ability to access new information.