(Patent attorney) The patents in question are continuation patents. Essentially, Nintendo filed a patent application before Palworld was released that disclosed the mechanics Nintendo is patenting now. That original application only included claims covering a subset of the mechanics described in the application. They can continue filing additional applications with new claims that cover the mechanics described entirely in the original application and get the benefit of having the priority date of the original application so long as they meet certain requirements about the timing.
Original application: I invented A, B, C, D, E, and F and want A protected; here’s some $. Follow-up application 1: I want invention B protected, here’s some more $. Follow up application 2: I want C protected, here’s some more $.
Part of the idea behind it is that you don’t have to waste money protecting parts of what you invented that don’t pan out (additional claims cost additional money beyond a certain number of claims). It’s not particularly fair, since you can watch what a competitor does (as Nintendo has done here), and essentially backdate a patent as though you had filed for it before the competitor did their thing.
The terminology can be confusing, but "copyrighted" is often used interchangeably with "registered". Copyright in a work exists from the moment it's the work is created, but it's not "copyrighted" in the sense the judge is using until the work is registered with the Copyright Office. Registration is a requirement to sue for infringement. So a work is protected by copyright as soon as it's created, but it needs to be registered before one can sue for infringement. That can be done after the infringement occurs. For example, if a work is created in 2020 and someone infringes on the copyright beginning in 2021, the work can be registered in 2023 and the creator can sue for the past infringement (though not all of the same remedies are available).
The issue here is that the artists are making broad claims that DeviantArt infringed all of their works (by letting them be used as training data), even though they didn't register all of their works. Only some of the artists that are suing registered their works, and they may not have registered all of the works they are suing over. That's what the first sentence in the next paragraph is about: "[E]ven if plaintiffs narrow their allegations to limit them to Output Images that draw upon Training Images based upon copyrighted images..." The judge didn't misspeak here.
Original application: I invented A, B, C, D, E, and F and want A protected; here’s some $. Follow-up application 1: I want invention B protected, here’s some more $. Follow up application 2: I want C protected, here’s some more $.
Part of the idea behind it is that you don’t have to waste money protecting parts of what you invented that don’t pan out (additional claims cost additional money beyond a certain number of claims). It’s not particularly fair, since you can watch what a competitor does (as Nintendo has done here), and essentially backdate a patent as though you had filed for it before the competitor did their thing.