Originally Posted by
pauldb
Which makes it strange that the OP's SEY flight hasn't also appeared. Maybe they are still finalising decisions ...
One thing about the other routes which have now been filed: they are all routes which will continue through the season. If SEZ is seasonal, and so the winter 2018/9 season is missing just that one single flight, I wonder whether BA will do the remainder first, and then find one empty LHR landing slot at about the correct time in the afternoon of 28 October 2018 before they file the schedule for that flight. All that is idle speculation, of course.