I doubt WifS shuts down worlds unless they're completely empty. And there's about zero chance anyone who has one team that they've built up and spent literally years getting to a high level D team would abandon said team. But I would not be interested in hearing how they want to play humans.
We, as humans, have to accept that there will not be a new user explosion. World population will be about 1/3 til the end of time if the humans interested in this game don't congregate in a specific world. Sort of the Rupp experiment which added 30some users intent on working their way to D1. Which, if people were actually interested in playing humans, should have been much higher.