And I did acknowledge in the OP that faction imbalance cannot be combated as a whole. And of course, it is player driven. But to repeat once more, we aren't talking about a "minor" 65-35 faction imbalance. If left unchanged the data we have available shows us that every single server ends up as a single faction in a very short amount of time, drastically and permanently changing the way the game is experienced for both factions. I am not aiming to perfectly balance the factions, but this one relatively minor change will single handed remove a huge incentive for PvE guilds to reroll to horde.
And yes, faction locks are most likely needed as well. What do you believe will go down better with the players: Faction locks or every single server being Flamelash-EU?