The Copyright Office issued a guidance report that states that content created by AI is not copyrightable. It doesn’t matter how complex the prompt is, the product is not created by a human, therefore, it cannot be copyrighted. In the Copyright Office’s view, the human is simply accepting the creation of the AI.
Works created by a human with the aid of AI, may still be copyrightable, but the AI elements may not be. For example, if an author uses AI for an outline or suggestions for song lyrics, the content the human creates may be copyrighted. If a movie uses AI-generated special effects, those effects cannot be copyrighted, but the movie as a whole can be. AI-generated work that has “significant creative modifications” by humans may be copyrightable. As always with copyright, there are no clear definitions, what are “significant creative modifications”? That needs to be specified through litigation on a case-by-case basis.