EI will use T3-F in SFO same as United for most flights and not the International T1-A.
Also T1 at YYZ
The airline will have an uphill battle to regain trust in the tech and pharmaceutical sector after pulling the San Francisco service. A service which was said to have been 'exceeding expectations' and then suddenly wasn't.
Most of those I know rebooked on United and BAW through Heathrow and committed to travel packages with them. So there will be additional ramp-up lag as those expire.
Its these IT companies who are paying for x amount of seats per flight each over a 3 year deal as far as I know.