Since the population for the game is theoretically growing, what SE does instead is lock the over-full servers to new character creation, and encourage people to plop onto the lowest population server instead.

It will be a few years before SE considers server merges. As Sove said, they're far more likely to to encourage people to transfer off the over populated servers than they are to merged two lower population servers.

It wasn't until most of the XI servers had a prime time population under 1000 that they merged them.