The question is going to be how much human intellectual input there was I think. I don't think it will take much - you can write the crappiest novel on earth that is complete random drivel and you still have copyright on it.

So to me, if you are doing literally any human review, edits, control over the AI then I think you'll retain copyright. There may be a risk that if somebody can show that they could produce exactly the same thing from a generic prompt with no interaction then you may be in trouble, but let's face it should you have copyright at that point?

This is, however, why I favor stopping slightly short of full agentic development at this point. I want the human watching each step and an audit trail of the human interaction in doing it. Sure I might only get to 5x development speed instead of 10x or 20x but that is already such an enormous step up from where we were a year ago that I am quite OK with that for now.