It might seem silly to ask this, but considering GGG doesn't have the best track record in finding and fixing those weird behaviors on the code of the game, then I hope GGG has actually reproduced this new infinite trial duration bug in order to make this claim of yours and they aren't just relying on the way the system was designed to affirm that.
Moreover, even if players aren't gaining delirium progress to juice up their drops, can't they still get a standard amount of drops from delirium mobs that continually spawn, since the delirium countdown timer is frozen by the infinite ultimatum duration?