No, because OP implied that the AI generated content inherits the LICENSE: in their view, if the input has been GPL, The output must be GPL. So if the input hasn’t been licensed at all, the output cannot be licensed. The inheritance of „no license“ is not „no copyright“, but „no license“. The question of copyright applies hasn’t been definitely answered yet, but just because it is likely that the person PROMPTING the AI doesn’t gain copyright, doesn’t mean that an output that is 1:1 derived from copyrighted material loses its copyrighted status. That would be truly ridiculous.