AI is just showing us a fact that many are unwilling to admit: everything is a derivative work. Much like humans will memorise and regurgitate what they've seen.
But the term "derivative work" has specific legal meaning. For example wikipedia states: "[derivative work] includes major copyrightable elements of an original, previously created first work (the underlying work)".
I would say that while that might be the case for some AI creations, it is certainly not true for all (or even a majority) of them.
