I think it'd be fairly likely that they'll keep the '2 hard modes and 1 totally new' pattern and we'll get a patch 2.6. My guess is that it probably won't have anything comparable to Coil/Crystal Tower Saga, but would instead have significantly more story to it, as a way to really set up the expansion, where we'll be going, and what it'll be about. If there is a trial, my guess is on it being Omega Weapon, based on the 2.3 story.