Right before boarding PIT-CLT they cleared one customer who is number 19 on the upgrade list
That customer isn’t on the standby list either so I don’t think it is a non revenue passenger.
It’s a short flight and I am not number 1 on the list so I am fine with sitting in Y. Just found this odd especially with someone close to the bottom of a relatively long the list clearing. F was booked full for days and they only cleared one person at the gate.