My DP. I am UA Plat. I had a flight from BOS-ORD late last year with my 2 minor kids with no status. These were in paid Y in economy plus all in 1 row on 1 PNR. Was not even thinking about being upgraded. As we boarded, my seat changed to a seat in F and so did my daughter's. I let my son take my upgrade. F went out full. They both enjoyed it. Was this not supposed to happen? Fluke? Just curious.