Arguably, this has already happened at least twice in the past. One with the discovery of the Black-Scholes model, and arguably again with the advent of HFT (and the ability to basically front-run trades).

The interesting thing about markets is you generally can only make money when things are mispriced. This limits the total potential gain even for actors with perfect information.

Suppose we did have an AI model that could with near certainty predict both the future cash flows of a company and future interest rates. You could very easily calculate the discounted cash flow and determine the fair share price today or at any point in the future. Rather than collapse, markets likely become more stable and stocks would perform more like bonds.