Nothing stops anybody from suing anybody else (and maybe even winning) though. What Napster was doing in isolate was just a technology yet RIAA and others sued and the lawsuit had led to the conclusion that the tech could be held reliable and if what users were doing were an intentional known to the tech-creators.
So the mere knowing of it led them to lose it and Napster died because of that but also the actual nail in the coffin was that they couldn't significantly do anything to the problem about that given its P2P nature, Ipods were around the same time and RIAA was a bit afraid of that too but Steve jobs assured them that because of the walled garden they could better control the piracy issue and have proper ways of countering it.
Now aside from the interesting details of that time I showed, coming to my main point, Lawsuits can sometimes happen for lesser reasons than or just limited to plain and simple license violations and if a company is earning 20 Million dollars supposing so, then they might also have a really good lawyer insurance package and could lawyer up just as well.
The core argument lies on proving if AI weights are copyrightable or not from my understanding because the licenses could be best applied under copyright material not public domain materials and the other discussion[0] by @cosmojg shows the most likely cases of AI not being copyrightable?, so you would have to prove if AI is copyrightable or not.
Now that would be a fun lawsuit to watch though.