A couple of weeks ago, I called the Diamond desk during a mechanical issue in Atlanta where it was not clear if I would be better off waiting it out or going with the later flight. The later flight was the last flight of the night and there was space available. I asked them if they could back me up on that flight and they told me they had stopped this practice. The rep was very nice and explained the change was calculated as the "backing up" process made it almost impossible for them to know how much inventory was really available for the flights. I get that and understand why they might have made that change but do wish they gave it as a perk to their highest level fliers. Has anyone else heard this?