North opened in 1988, the same year BA bought BCAL, giving them a major presence at LGW. In the planning stages, there's no way BA would have filled even the stage one North Terminal, (todays Pier 5, albeit less three of it's current gates). British Airtours were based but BA had a few Channel Islands routes and, ISTBC, no based heavies.
I don't believe CX, who are currently operating one out of their five daily LHR slots will open LGW in Oct, stranger things have happened but they may well open bookings and simply bank the cash and move the flight to LHR. As for Norwegain opening transatlantic long haul in DECEMBER in the deepest collapse in traffic in peacetime, probably not IMHO.