I see what you're saying, and defining what makes art is nebulous to the point of being impossible. Rather than a positive proof, I would just counter by asking whether you think art can be defined purely by its aesthetics, or by virtue of the methods used to make it - that is, without considering at all any concepts or ideas put forward by it.
It's got to be a combination of both (e.g. made from wood and shaped like a ball but feels like this in this room etc) but maybe that is too neurotic and not conducive to new aesthetic experience. I think my pattern recognition for generative art would be quite high based on how many times I've seen it as a style of art previously. For most images i've seen DALL-E has all of the fingerprints of generative art and on some level I notice that even if the fidelity is approaching something that takes over aesthetically (e.g. where those kinds of perceptual fingerprints fade away a little bit).
