Yes, I think today's faction imbalance is a social issue now, as it has been a long time.
To solve the faction imbalance, I can only think 2 possibilities:
1. Remove faction
2. Give alliance massive racial advantage until pop is balanced.
I don't think 1 is a good solution for wow as an MMORPG and I don't think blizzard will do it.
And I really doubt Blizzard will do 2 either.