Originally Posted by
3Cforme
People will clear off the waitlist as RM opens up inventory. Unsold seats will go to the gate for clearance of GUCs. I don't even see a point to the OP asking.
That is the theory but in practice I've called in to see that a GUC was correctly applied and was told that upgrade space was available and been upgraded. Maybe it works now, but in the past it was not automatic.