TCX are pulling out of MAN-Canada and so next year Air Transat are taking up the slack with 10 flights per week. Not sure how that breaks down across the destinations. YVR tends to be a summer-only route.
As for AC, true, they apply for slots every year and then hand them back. Not sure what the game is there. bmi may not be flying MAN-LHR next year (they may not even exist) and so it could be different.