Originally Posted by
Rivarix
Full-fare Y ain't competing with the cheapest J for op-up - one is looking for op-up to PE (or J) while the other one is to F. It matters when both are travelling in the same class.
Mmmm, unless the high value PEY passenger gets op-up'd to F instead of a lower value J passenger.
Or alternatively, a high status passenger who is flying Y this time misses the op-up while a low/no status passenger also flying Y gets the op-up, because they are worth more $$$ to the airline.