It sounds like they were originally going for a server like EQ2 had where it was a progression server "Race to Trakanon"
- the goal being the first group to kill Trakanon (a raid boss) with Rewards for different accomplishments along the way. Once that goal was accomplished the server was shut down and characters transfered to the existing ones. EQ1 does the same thing.
I saw AoC is also going with a TLE (Time Locked Event server) so it's getting to be a thing now.
Currently installed: WoW, ESO, Neverwinter, W101, P101, GW, GW2, DCUO, EQ2, SWTOR , LoTRO - Diablo3, Dragon Age 1, Torchlight 1 &2, KoAmalur, Sims 2&3 plus 100+ casual games ....