Follow-up: was upgraded on the plane. There was an open seat in FC and the GA came on-board and said to the FA "We have a platinum in the back and we're going to move him up." I was lucky that it was me. Strangely, though, the guy next to me was gold (per his BP) and his colleague in front of him was Silver (per their conversation). I'm still not convinced that the process worked correctly, as these guys were UG at the window (there were no UG given at the gate - in fact, the other GA told me that FC was booked full and didn't even look at my BP. NWA.com confirmed that FC was booked full).

Crazy...but at least I got to sit up front for 36 minutes.