1. Everything before WoW does not matter in fact the Gilneans weren't even part of the Alliance back then and only joined after losing their homeland. So the Alliance never really had to begin with. Also when changing to Worgen didn't they forfeit their right to the land anyway? Worgen afterall aren't humans and thus the original Gilneans went extinct.
2. Do you have any Alliance point of view quests or lore developement to back this up? Was it mentioned on the Alliance side at any point? No? Right! See?