Agreed. Sounds like it was a by-the-book GA who said if you board, your name comes off the UG list. Well, everyone boarded and the seat was open so it went to a non-rev.

Also agree this is a poor policy but as long as it exists, elites need to ask if F boarded full, not just checked in full. If there is an open seat, ask if you will get it if you hold back on boarding. But don't wait until boarding begins because at that point, the last thing on a GA's mind is upgrades.