Yes, after class orders aren't enough:
Death Knight becomes new Lich King
Paladin becomes leader of Army of Light
Warrior replaces Odyn at the throne in Halls of Valor
Priest replaces Prophet Velen as leader of Exodar
Shaman becomes new Aspect of Earth
Mage becomes new Guardian of Tirisfal
Druid takes Ysera's role as Guardian of Emerald Dream
Demon Hunter absorbs Kil'jaden's soul to become new leader of Burning Legion (there must always... be... a Legion Lord...)
Hunter adopts bear cub, raises it, and together they help establish New Orgrimmar after the last one was destroyed by demons
Monk goes full Emperor Shaohao and hides whole planet in mists so Sargeras can't find it
Rogue keeps doing shady stuff.
While Warlock creates his own Shadow Council, and plots to get others' powers for himself.
I reckon they will keep Order Halls. They can pretty much function easily as a separate commodity, remind a little much like the cities just minus certain commodities of course.
They could add more to it without having to place anything overbearing or whatnot, add storylines to it and so forth. Can easily take away from it the current legion stuff if you think about it because really well you get a missions board and places to upgrade your weapon, can be edited well given a good enough reason. It's quite a vehicle and to be honest, you can still downgrade the player because someone has taken the mantle since you as the leader have stepped down. Everyone assumes it will get bigger and better because that's how the game is gone but the story can quite easily do a Thrall .
If we are carrying forward the post leveling leveling system that the Artifacts gave us in some other form, I bet we would still see their use. Possibly a HS to directly port there and it can still be used in the future.
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Worst decision they made for WoW was to have the factions be separated. After WC3, it would have made sense to if not merge allow the factions to interact with, party with and raid with each other. In Alpha you could group up and talk with opposing faction members at one point. They could have easily kept them separate for the illusion of factions for PvP. PvP could have been war games to keep the factions fighting skills sharp and ready.
They won't remove them. They'll just make them not generate anything profitable, like garrisons.
You're getting exactly what you deserve.
Another N'Zoth+Azshara discussion. That's as exicting and original as all the legendaries threads.
Honestly, I think it's time for WoW to move forward, and back, in a sense. I know I'll likely be in a minority on this idea, but:
Players need to be adventurers. They've been through enough, seen enough shady BS on both sides, and unified both Horde and Alliance races under common purposes and under their Class Halls. It's time for the players' characters to carve their own paths.
No more Horde/Alliance faction for players. Let adventurers party with adventurers, across racial divides.
In the meantime, Horde/Alliance politics can completely fall apart. You can have them at all out war with the players capable of taking part or opposed to it, even capable of opposing their traditional faction side. You could have inter-faction squabbles with NEs opposing a decision by Stormwind resulting in NE/Tauren vs Humans/Dwarves, etc.
EverQuest went this route and it worked just fine. All the racial cities were extremely prejudiced, but adventurers (being basically mercenaries) could party with whom they pleased. Because out in the wilderness when you're life's on the line, that guy willing to stab the monster is suddenly your friend, regardless of how you feel about each other back home.
And while we're at it, another little gem I'd want to see stolen from classic EQ with this? Guilds at war. You're not PvP flagged to everyone, but if your guild is at war with another guild? You're PvP flagged to their members. Each guild's leaders form the agreement on spoils of war, allowing a limit of money/items to be looted, which worked in EQ but would likely be a complete clusterF in WoW.
Honestly, there's a LOT of story opportunities they could open up if players were unchained from the faction war - including even more heated stories involving said factions at war.
How do you end war alliance? When war is over.