I warned about spoilers. So i am not really sure what Blizzard is doing but as you see now that Vol'Jin died they replaced him with Saurfang in Orgrimmar..... well however it looks like Saurfang dies aswell while fighting a lot of demons with you (the player) in the Warrior Order Hall campaign and before his death he tells you ''i wish i could kill a few more demons with you etc''. The only thing that comes to my mind now is that they'll bring Thrall in Orgrimmar throne again, otherwise i can't think of anything else.
Now for Exodar, no matter what class you are at the end of the artifact questline everyone ends up in a final scenario where Velen's son who is an Eredar attacks Exodar, while you are fighting Velen's son, Velen turns against you and you fight both of them, when Velen's son dies Velen gives you the light's heart and you get it to Khadgar, then Velen says that he is no longer a Prophet and he orders the draenei to prepare the Exodar and launch it to Argus to get revenge against Sargeras for turning his son into a demon.
This is all, although the second event i understand it but the first not really because Saurfang's death was really random and hidden only for Warrior class...