Originally Posted by infinityplusone
My question is, if I had upgraded would that have upgraded my class of service, to be able to gain more EQM?
You shouldn't. It most likely would have posted as F/Y (class flown/paid), and your miles would be based on the class paid. Although it shouldn't matter for you anyway EQM-wise: Y earns a 50% EQM bonus same as F (Y just doesn't get the 50% banked mile bonus for paid WBC/FC).