With the world visit system, the "population" issue is essentially solved.
Being on the big servers now is like living in the big city instead of the countryside. Rather than the walled-garden situation it was previously.
So folks can have their houses in the suburbs/countryside, but come to the capital city to socialize if they want.

Of course, this is until they put servers as congested again (I really hope they don't) and said servers can't be visited.