I don't think that's true. I can't cite them off the top of my head but when I read about supreme court cases often a big point of contention of the ruling is whether they decided to issue a narrow or broad ruling. Sometimes they decide to hear a case or not based on whether it would serve as a good basis for the type (narrow/broad) ruling they want to issue.
And the legal universe is vast with new precedent case law being made every year so I don't think the corpus of undecided law is confined to well known legal paradoxes.
As for this case it doesn't seem that odd to me that the issue of intent has never been at issue: I would expect that typically the intent would be obvious (as it is in the OpenAI case) so no one has ever had to decide whether it mattered.
Just seems like this area isn't that exotic.