Locked status on worlds will remain until those worlds no longer experience high daily queues. I completely understand that it can be a huge bummer if you want to be on a specific server, but queues are often the result of people all congregating on particular worlds (in addition to merges). And if we opened the world for these occurrences above, it would contribute to growing queues to which create other unhappy problems – like people having to wait hours to get into their world.
We have attempted to limit this problem a bit more with our new Inactive Character System, but again, if the world is already experiencing high queues your best option would be to have your friends move to a world you all can participate on (and if their accounts qualify, they may already have 2 free transfer tokens to utilize) or perhaps wait several days for some world population shifts.