Why so you can change the timeline and seize the crown from Thrall when he invited you to join him in Durotar and you declined? Because you have my axe if you do - the Horde should have stuck to its wild roots!
Don’t need a new client to put Thrall on the throne in Stormwind.
If they can do events like Battle of Undercity, or that event where you bring in Onyxias head, I bet you could script a cool assault on Stormwind and put Thrall on the throne.
Hang some Horde banners in the walls.
What they probably can’t do is the whole phasing thing and keep him there.
A Horde assault phase that sticks around is doable if you add client modding into the mix.
The possibilities are really endless. It’s totally impractical but the thing I’d like to do is a “unified” Azeroth that treats all the continents as a concurrent whole, much as Kalimdor and Eastern Kingdoms were with the original game, instead of most continents being siloed expansion experiences.
A whole bunch of state such as this is stored in the MySQL database rather than the client/client files, so it's definitely theoretically possible to spawn an NPC of Thrall on the throne in stormwind.
