While we are supposed to get Urth's Gift as a trial coming up, I don't think that's the only 'primal' fight we'll be getting. I'd be willing to bet we'll see an Omega Weapon trial (Possibly with an EX/Minstrel's Ballad version) in 2.5 as well, given it's been being brought up in the story for a while and it'd be a fairly fitting end to the 2.x storyline.

(My ideal would actually have it at the end of a Praetorium HM but who knows if that'll happen)