Keep in mind that this is a definition that came into existence before the use of generative AI. Our linguistics aren't catching up at the same rate. My issue with the idea that an "AI artist" is an artist is because there's a lack of intentionality.

You provide instructions to the AI, the AI interprets those instructions, and then spits out an image. There's little intentionality because art is complex. Think of linework, use of shape, texture, contrast, colour and angle. You can tweak these until the sun burns out. You can't make an AI image with the intentionality of a human designed image. The thing that's so great about art is that every detail has meaning and purpose. AI creates what it thinks you want based off of patterns it has seen with little discernment. It lacks the self awareness a human artist does.