As to phasing or changing zones to impact some treaty where by Alliance takes back zones A, B, C etc, it won't happen purely because it would mean they'd have to spend more time between xpacks, constantly changing zones from one faction to another as the flow of battle passes over the lands.
Been playing this game 8yrs now and tbh I'd rather not have to spend as long between expansions as we did in the past. I don't mind 18months to a couple years per xpack but if they had to start messing with zones on a regular basis constantly updating them to reflect the current conflict between factions, then we'd be looking at expansion duration times like we had previously:
1994– – Warcraft: Orcs & Humans
1995– – Warcraft II: Tides of Darkness
1996– – Warcraft II: Beyond the Dark Portal
1999– – Warcraft II: Battle.net Edition
2002– – Warcraft III: Reign of Chaos
2003– – Warcraft III: The Frozen Throne
2004– – World of Warcraft
2007– – World of Warcraft: The Burning Crusade
2008– – World of Warcraft: Wrath of the Lich King
2010– – World of Warcraft: Cataclysm
2012– – World of Warcraft: Mists of Pandaria
2013– – Hearthstone: Heroes of Warcraft
And I'm sure no one wants another fecking Dragon Soul lol...
Banging away at places in TBC was fun for me, didn't mind the grind through linear experience and gating/attunements but the player base nowadays is impatient. You only need to look at the fact blizzard put LFG, LFR and soon Flexi in the game to see this. Hell they even made it so EVERY player no matter their play time can get a legendary and yet even this is still being bitched about because it requires some effort to farm certain parts but it's nothing like it used to be.
If they start taking longer between expansions and leaving us to grind away at some crud like Dragon Soul again then it's only gonna hurt the game as a whole rather then actually making any decent kind of impact just so those who want X zone to be returned to Alliance/Horde hands over and over when the developers could be working on not only newer content but also get back to working on Titan and other projects (insert Warcraft movie here finally).
I love the Warcraft lore, I really do, it was reading the books that actually got me in to playing the online game in the first place, more then if I'd just played Warcraft 1, 2 and 3 would of but to actually have the player base wait long times between expansions and content isn't possible any more.
The other side of this coin is this:
If there was to be any kind of lasting peace between the two main factions then pvp wouldn't need to exist any more and I can tell you now, that would cause more of a s*** storm then any nonsense over who controls what zone, so in short these places have to remain as they are so they can be constantly contested for.