I’ve never noticed that actually. But, 114 was upgauged from 321 to a 767 and immediate same day upgrade space became available. My timing was perfect and I got a seat in J.

34 did seem to change from a 77L to a 787 and back. And, a goood thing I changed flights as even my SE friend got one of two seats in PE. I woulld have been back of the bus.