They should do this for Aether, too. Right now it's really frustrating to wait in party finder forever, unless you forsake doing anything else in the game and sit on Aether. There's no point keeping it locked to "protect other servers," because they're all already dead. Preventing using PF on Aether might help, but it'd be overall worse, because the Dawntrail playerbase has died down so much that you'd be spending a long time in PF anyways.