Try this for example, 20k people waiting for 2.0 see this, then they decide to choose a server and never come back, the server will get capped and people who want to play the game will be on what will become slightly less populated servers, or use up names other people want.

I remember every time a FFXI server merge was coming people would pay the extra pound to make a mule on thier destination server with thier name, they then delete the mule and reserve thier name, or trolls making mules to stop people keeping thier name. This can all happen with allowing inactive players to choose a server.