All of the recent adds to West Coast-Europe have been ex-SFO. I think it seems pretty clear that UA is not going to add many (any?!) international routes ex-LAX in the near future, despite what past rumors may have been. Giving up on LAX-SIN after 1 year is a pretty good indication of the level of tolerance they have for seeing how things pan out there. They were pretty quick to pull the plug on the second LAX-LHR frequency as well, IIRC.