They've been showing it... slowly, and not in the zones that actually needed it.
For some reason every zone they pluck out of Cataclysm, HD-ify, and then invade by Orcs or Undead are the zones that aren't still literally burning in the immediate aftermath of Deathwing showing up.
Those are the zones that most need a revamp, and by now the quests have aged so badly that a lot of zones need those redone too in a lot of zones.
Hell Silverpine starts with the Dead Evil Ex-Warchief calling the Paying Pennance in the Maw Evil Ex-Warchief a Bitch (well that was censored but point still stands) because the latter isn't respecting the former's post of Warchief.
Of course none of this matters because Blizz was able to sweep the problems under a Chromie-shaped rug.