Amplifying information
Thanks for the comments.
The ticket was purchased one week in advance so it wasn't a last minute deal. We did have the option of USAirways back to Reagan National but since capacity reductions USAirways no longer flies an afternoon TPA-DCA run. We'd have to wait until 6:30pm.
When discussing this with the UAL attendant she tried to explain how my seat assignment would depend on how many others opted to upgrade to E+. So in effect what they do is "shuffle the deck chairs".
I was not implying I deserved an E+ seat. But from my perspective, I paid full fare, refundable. If E+ was all the seats that remained open on the flight, then put me in that seat and move on. No need for this kabuki dance at the gate
Nervous traveler? No not really. Just one who like efficiency and proper customer service.