Even in low season BA has very often full flights, especially Fridays and Saturdays out of SFO.
What amazes me is that with all the premium pax out of SF, they still use the old 747 in all classes, exception being the one-off times when they have New F (for the few lucky ones). If they would upgrade to A380 they would still make lots of $ on it, as now people travelling to Asia and Africa use CX, EK, SQ, OZ.
Wouldn't it have been better to postpone a route like LHR-AUS-LHR until September and move a 787 to SFO, and then ask AA to add a flight to LAX-LHR instead of opening new routes to Europe?