Quote Originally Posted by Yasminou View Post
You can queue as a party for expert.
The only thing I see is that the DF found you a full party but all instances are taken, therefore a reservation is made.
Pretty much this.

In the past I've queued up with a full group, tank, healer, and two DPS and it would reserve an instance and we had to wait a minute to two. Haven't seen this recently though.