Brain Pharts 8.2.5 and Beyond.
Finish last fight in 8.3, cut scene rolls. Wrathion has found a way to clear the purge of all of the old god corruption by triggering the origination array . Unlike our encounter in Uldum, we won't avoid the full re-origination. ( screams and fade to black ) Next we wake-up back in Orgrimmar/Stormwind to find ourselves no longer level 120. Nope instead, the world has been rebuilt to a date roughly in Earth 2006. Yes, the level squish will see us back at level 60 as if we've just completed Vanilla experience. ref: DenOfGeeks That new level 60 content won't be added to Vanilla. It will be the next expansion where we don't repeat our mistakes in Burning Crusade.