is it possible to bring back the elites as playable?
I suppose ill save you some time.
Nope, but perhaps in Halo 5.
It would have to be programmed in, and seeing as the game is already released the answer is no. Look forward to Halo 5 though, they may be in there. I look forward to it myself, I miss those big dinos. For now, if it’s elites you want, play Reach or H3.
There seems to be a lot of stuff that 343i decided not to implement into the game, despite it being in previous titles. Its a shame, and I hope they improve with halo 5.