It depends heavily on the AI system used. There are instances where the system put forth artwork with resurfaced signatures. That is only possible, if that signature was stored. Besides being quite embarassing.
We are not quite there yet, that the AI systems really learn how to draw, but if we were, yes, banning them makes as much sense as baring students from studying artwork that they could use as reference for their own style. A glaring example can be seen in those AI systems that make pictures of people with fused body parts and extra hands, fingers and so on. They do not grasp how a human is supposed to look like. They just garble whatever is associated with the prompt and the AI operator can sift through 100 pics to get a good one.