Thanks for the comment. Except that the "wait-listed" segment that used to be in my reservations (showing waitlisted for R) has dissappeared and the reservation now only shows the Y segment. My name is also not showing in the upgrade list. So, AFAIK the upgrade request has completely vanished or it is hiding in some "secret" list that I can't see until the gate (and by then it will be too late). Not a major thing for this short flight, but if this was a transcon then I would be very unhappy.
Pegardless, does then the memory of when the upgrade was requested vanish at T-24?