Grosh-Nak is high on our list for kingdom reworks. So a Gar’Nok buff won’t happen until then. Khaziel is also on the list as well, but we don’t have ETA on when either will happen though.
So Ogre is a troop that is unlikely to a buff (at least to his spell), as he is one of the first troops encountered to new players.
With the Roc, we may look at a buff for him but it would be after level 15 for him, as otherwise he becomes a little too good in the arena.