I posted this back for the Tide of Vengeance PTR:
I stand by that still.
To be fair, the statements from Mathias and Nathanos would come well after the time period the Mission Table missions were first available.
Crazy enough, we per-emptively basically already get it with the saving Baine scenario.
I predict the raid will actually be Siege of Stormwind, and both Horde and Alliance will be racing to save Peach Anduin from Bowser Sylvanas.
I could definitely see Blizzard doing this so everyone can blame the Night Elves for the war continuing just when peace was going to be possible. Just to kick the Night Elves into the mud another time for good measure. (I also like Saurfang and I would rather see him try to atone for the War of the Thorns, so him dying in general would bum me out in general, too.)
However, at this point it would be the more obvious thing to do to have this all wrap up with peace between the Horde and the Alliance as per the MoP 2.0 script, so I find it more likely the Night Elves will just agree to peace and probably start working with the Horde again like at Mount Hyjal and Val’sharah again.