Hey Blizzard, this statement seems to have failed, unless there are a whole lot of people deleting their characters all of a sudden.
Right now only Herod is high, and even Faerlina is Medium. However, during the early name reservation, almost every server was High. So unless people are actively deleting their characters on Faerlina and other previously High Pop realms, this indicator is NOT showing the number of players rolling on these servers, but rather the number of people logged into the server in the Client.
Which is a pointless metric right now.