Fourth Estate Public Benefit Corp. v. Wall-Street.com was a motion to dismiss case regarding the timing of a certificate of registration. That being said, the basis of copyright and the right to statutory damages is not a nuanced issue.

(Since you are probably not an attorney given your reply), I will clarify what you perhaps consider to be confusing: Everyone is afforded copyright in their original works. I am afforded copyright in this reply. If you republish it without my permission, I can sue you.

Let's say you took my reply verbatim and then put it inside your Medium story. In my hypothetical scenario, this upsets me. I want to sue you.

When I register and when I wrote this reply are the important factors in what damages that I receive. So it is not that I cannot sue, it is a matter of how much I can sue for.

I invite you to read up on the Dorland v. Larson case, as an example of what happens when someone does just as I hypothesized above. (It made national headlines recently, so it is easy to Google.)

Again, the confusion you have is about damages. If you don't register in the statutorily defined time (registration also being the gateway to a lawsuit), then you lose certain statutory damages. However, you can still sue for actual damages.

So let's say you serialized some fiction on Medium, and then HBO decides to make a big TV production out of it. You failed to register your copyright in time to qualify for the statutory damages. (You registered prior to filing the lawsuit, though.) You sue for actual damages. Given that it's HBO, your actual damages would probably be in the millions.

But here is the thing about writing stuff on the internet: while paying the $35 registration and filing for copyright registration is all well and good, no one is going to register their copyright on something they wrote on the internet unless he or she believes that it will one day be profitable. Will you register your story (this one)? Most likely not.

To me, that is the crux of the AI issue. It isn't a matter of whether it's transformative use, fair use, or permissible use. I foresee tons of copyright trolls attempting to copyright things that an AI wrote, and then suing people when something else looks too similar ... because it is, after all, an AI. The percent chance that it will duplicate something it once wrote is high.

This is not legal advice, and we do not have an attorney-client privilege.