Highly populated servers often have a login queue of over 60 people and thus would like to have some form of control over prioritizing who is getting in first.
A list of priority players, identified by their GUID/SteamID could help, by putting the matching players in front of the queue when they enter the server.
This way admins have an opportunity to get onto their own server without having to wait for all other players in the queue to join.
Quickly reacting on events in-game, is not really possible if one must wait for half an hour until they get to join the server.