Are there some upgrades you always/never get in a game? I'd say a lot are situational, but there are some that we never seem to get:
Greater demon upgrades- You don't place greater demons in new territories often enough for Nurgle's to seem worth it (or at least you'd never get it before his other upgrades). Khorne doesn't really care about victory points from domination. (Side question: if a khorne unit controlled by Slaneesh makes a kill, does it count towards Khorne's dial advancement?)
Bloodletter upgrade: We didn't see why Khorne would care about saving a unit or two as long as he killed someone. Cultist upgrade seemed more important to cheaply spread out as much killing as possible.
Plaguebearer upgrade: The one hit back wouldn't matter much against high defense low attack Slaneesh or Tzeentch's warriors, and the whole idea against Khorne is to not get into combat (or at least not die) in the first place.