Let me add a few numbers in here to deepen this discussion :
There are currently 100k registered users, which only around 6k users are continuesly active (adding server capacity and timezone difference to that)
Also ; The only users that have priority login are staff members, which doesn't exclude to server capacity (Example : If the current online user count is 1800/1800, it will be 1801+/1800 when staff logs in) If a similar method were to be added for Membership users, the server capacity would be overflooded and cause it to crash, instantly. On that regard, priority access is unlikely to happen.
However, increasing our capacity is within our developement plans. So, in the long run having more slots for all of our players rather than having "If you want to play, you better pay" as a policy is more feasible for our game.