Well to be honest, after the first Ruiz fight, nothing would surprise me. I would pick AJ for sure, but Pulev is technically sound, has a good jab, and can counter fairly well. He did get KOed in only the 5th vs Wlad, but he DID land some decent shots on Wlad, better than anyone for quite a while before and after, until AJ. Landed some better shots than even Fury.
Even in the second Ruiz fight, AJ did get tagged a couple times and reacted to being hit very poorly. Pulev could make it happen, and if AJ takes another loss, I bet he would retire lol (I would also, with all that money)