I don't see an easy test here. Worse, I see the beginnings of a test that is technical and very likely to not match the future of how we will interact with these things. We have to start somewhere but I'm not sure 'Neither mere prompting nor the selection between several AI suggestions is sufficient as a human creative contribution.' is the right place to start. I think we need more examples of what does constitute 'human-centric' and work from there. I also don't think that any system that says 'you didn't do enough work so it isn't human-centric' works. Any system like that will require a reexamining of copyright in general. There is a lot of low work copyrighted material out there. Just because 'AI' didn't build it doesn't mean the same tests shouldn't apply.
Some examples of why I think this is really hard: Say I build a story generation system. I work hard on building an agent swarm of actors, critics, editors, researchers. I craft into the various agents concepts of story arcs, outlining techniques, character development. I build a huge well thought out process for how to agentically write an actually good story, so long as you give it a title. Heck, I even design and train my own custom LLM with original layer ideas and novel training techniques to use on this system. After all that I then take that final step and give it a title. Do I have no claim to that? I probably put more work and creativity into it than an author would have a book. What if I then gave it 500 titles? 5,000? Would my claim degrade the more titles I fed it? Is it a percentage of work question? What is the core concept here that defines 'human-centric'? What is the cut-off here?
Let's go even further. I don't prompt. I live in a world with unlimited context models. I have a conversation about the book I want it to write. During that process I reject some ideas and accept others. I didn't give it a 'system prompt' but essentially all I did was prompt it and select versions I liked. Is that not human centric? How about if I asked it for advice and it did some editing work on my story? Did that make it not human centric even though the starting text was mine? What if that starting text was 99% replaced with a version 10x as verbose. Defining based on how you interacted with the model (prompted and selected) just seems way to weak to be a clear test.