I mean, that's pretty much a moot point if no publisher publishes under it, isn't it?
Saying something is a lost cause doesn't make it so.
Eh, if a court ruled that the OGL 1.0a could not in fact be revoked, deauthorized or similar buzzword by WotC, then I think at least the closer clones in the OSR would probably keep publishing under it, just because then they wouldn't have to rename spells and such.
Perhaps, you also have to factor in whether anybody trusts WOTC to abide by an agreement they made into perpetuity. Because nobody wants to be here again in another 20 years. That's the bigger factor, I think.
Nobody would have to trust them. They would have tried messing with it and a judge would have ruled "no, you can't". At that point, it doesn't really matter that it says copyright Wizards of the Coast on the document, it would be entirely out of their hands, as there would be a court ruling, not just an expectation based on what the document says and how and why it was designed, that WotC can't mess with it.
I never played original RIFTS, but the offical Savage Worlds version is a lot of fun to play.
I mean, it would depend on the ruling and on what grounds it was decided. Even in your hypothetical there isn't anything stopping WOTC from simply trying again with a different legal argument to rugpull the OGL again. I think the well is truly poisoned, unfortunately.
That assumes they learned nothing from this and they do try again. Also, theoretically every successive attempt should get even weaker, as they will always try to attack the 'biggest' gaps / loopholes, only for those to be shut
