Originally Posted by
javabytes
An announcement that "Passengers X, Y, and Z, please remain in the gate area for a possible upgrade." If you want the shot at it, you stay back... if you don't, you board... and the GA doesn't delay the flight by pulling up people on board.
I've heard AA GAs make similar announcements. I've also heard them make explicit announcements that FC has boarded full and all elites waiting for possible upgrades should please board.