Can machine learning/AI lower the security existing cryptographic protocols similar to quantum computers? Initial thinking would be not unless the protocol revealed sensitive local information that could then be analysed by an ML algorithm and applied globally.

local meaning I see messages from Alice and Bob extract some information x,
then apply x to all other users.

Not an expert in ML, this was just initial thoughts.
No.  Machine learning and AI techniques do not fundamentally change the computational capabilities of an adversary like a quantum computer does, no matter how much hype is in the air around ML and AI.