Originally Posted by
emanon256
Ive never been pro-actively called in these situations, its always been a shock at the gate when I try to board.
On this very route in fact, MCO-DEN, I was in Row 3, and due to a A320 to A319 swap got my F boarding pass taken away, and was handed an E- Middle. I was

That would be the difference between a planned schedule change in advance and an operational plane change on a one off basis once the airtcraft has been routed (usually a few days out, up until dptr.)