Perhaps in terms of willingness to pay, but that's DL's problem for revenue generation - not something a pax would care about. Otherwise, F is the same no matter if the cabin is full of paid pax or all upgrades.

I guess sure, maybe if there's some empty seats, the F/A could be a bit quicker about getting food/snacks and drink refills to you, but it delays drinks/tray distribution & collection maybe by a couple minutes at most if F is full vs. partially empty.