In principle by the way copyright works this isn't really an issue: if an image is generated independently then copyright does not apply. However, in the event

In principle by the way copyright works this isn't really an issue: if an image is generated independently then copyright does not apply. However, in the event that you wind up with something similar, it becomes something which you would need to prove (and people have lost cases because they could not). On the other hand, such large-scale generation of images will likely be treated differently by the courts than other means of production.