Spotty, I can only report what I saw on Manchester Airport website at around 3pm. Every Monarch flight to a Spanish destination had been cancelled. Meanwhile Thomas Cook and Jet2 each had a couple of departures.
I take your point that charter carriers are different, in that they tend to stick with it because they have to move their passengers in the end. But there's nothing to stop a scheduled operator doing the same, as Jet2 demonstrated.