>>719844285
I suppose it's never reeeeeally made clear in game, but the way you describe "rher still being around" is what the traces literally are. The traces are completely sentient and carry the same will/behaviours as the full old god (as shown with Gro-goroth in F&H1), so all of the actions you atribute to Rher needing to be around are all just his traces acting as he would, the traces are basically just a mini/less poweful version of the old god. The old gods themselves as are concepts, so long as the idea of them remains in the minds of humans then they continue to exist to some degree and their traces can enact their will (as stated in Father Hugo's God Manifesto), though even in universe the exact nature of the old gods is debated, which I find very interesting.
But yeah, I think it's extremely clear that the Rher traces triggered the festival to interfier with logics ascension, just how he tried interfier with the girl's ascension in 1 via Pocketcat and the lady of the moon. Pocketcat is taking order directly from the traces themselves, since for all intents and purposes they are Rher himself. Rher is a trickerster god who hates humanity, of course he'd get involved to try and stop humanity from ascending. I'm sure he tried to do the same almost 2000 years ago when Alll-mer acsended.