Looking at the scheduling for the two aircraft there seem to be just 2 or 3 spare slots left to fill.
virginblue
I think 22nd December is an excellent time to launch the routes on the Flybe website with most people having a lot of spare time to fill between Christmas and the New Year. What better way to occupy themselves than to book a holiday or two?
I do agree with you that a major marketing campaign to go along with that would be largely wasted and I'm sure this will be launched in earnest in early January.