To be quite clear: the dev team has no intention to destroy any realms on Dwilight to increase density. We certainly have no particular belief that destroying southern realms will improve matters.
The monsters being dependent on player density is not in any way intended to indicate that we want realms to be destroyed. We don't have a solid plan for how to increase density in a healthy way, but we do believe that doing so is necessary.
If players chose to abandon outer realms to migrate to inner realms and increase the density there, we would be very happy about it—but it would only work if they did choose to do it.
I do have, in development, a change that would stop monsters from hammering repeatedly on the chokepoints and instead spread their attacks out across the east: allow them to cross sea zones. However, it is still not quite working right.
