Originally Posted by
Steampunkette
... that would be amazing, but it would need to be one of the last things that happen in the expansion, and decided by the Arathi Warfront...
The reason Lordaeron is being left empty is because the Alliance can't defend it against hte Blood Elves that might march down to take it back. So Stromgarde and Arathi are being fortified to hold off any counter-attack while Gilneas is being used as the new Staging Point for the war effort (For now at least) according to the Devs during the Q&A.
I don't think the Alliance would allow the Nelves to take up residence in Tirisfal until the area has been more properly secured, perhaps after the Arathi Warfront is decided in the Alliance's favor.