Tbh PHL is a secondary destination for Scandinavians traveling to the US for leisure. Secondly, demand for US bound flights are very low atm in Europe (it may improve with the Middle East tensions). So no wonder if PHL-CPH is not performing well.

Had it been from JFK or MIA it would probably have been different as these destinations are in high demand for Scandinavians (I'm aware that DL and SAS are already flying to CPH from JFK), but who wants to go to PHL? Admittedly for some it may just be US gate way to a AA destination beyond PHL.