So the war becomes more intense in 5.2, with the sunreavers and kirin tor going full on against each other after the events of 5.1.
With the war having been pressed up in mists of pandaria, this is what the war hungry fanbase was asking for, and blizzard gave it to them.
But they also made something pretty clear in wrathions own words, that the war has to come to an end, and the fact we know both horde and alliance will be attacking orgrimmar to end Garrosh's rule as warchief speaks more to wrathions words in this.
But, the war has made things tense, and for there to be any reason thrown into it, there will have to be a voice, or many more then one, that is able to bring it to a stop storywise, that seems to be the running thread there, build up the war, and bring it to an end, since "WAR IS THE ENEMY", as spoken by metzen.
Like the voices of warmongers in being the ones who fuel the war, such as Garrosh, now Jaina, Sylvanas, and for a time Varian, who then will be the one countering this?
Anduin? After he recovers from his dire injuries brought on by Garrosh. Thrall? He's stepping back into the game with helping the darkspears. Vol'jin and Baine? Velen? Ji and Aysa?
However you might like to think your side will be the winning voice that only does so by shouting about destroying the other side, those characters will not ever be the voice of reason, because there simply will not be an end to the war by one side being decimated by the other side. The only way it comes to a head is having characters to dampen the fires, and either backing a pack of peace, of both sides walking away, and turf wars being brought back into it.