This seems... really poorly thought out, tbh. Tons of major studios are already using generative AI content as part of their creative pipelines. Photoshop has their new "generative fill" tool that is going to become more and more standard. The line between AI and not-AI is already blurry as hell, and going to get blurrier. Banning it outright is not remotely sustainable.
They're trying to preempt attempts to flood the storefront with AI generated shovelware. Adjustments can be made to policy down the road as needed, but for now this is a good way of preventing the signal to noise ratio from going out of control.