It is an interesting development indeed as it has not been tried elsewhere (other than in Switzerland with Helvetic's E190/290s) for a long time - operating an aircraft smaller than the A32X/737 for tour operators from "regional" airports. 20 years ago or so it was quite popular for TUI Germany (and other tour operators) to serve smaller German airports with BAe 146s. Back then it was said that despite the higher prices that could be charged for those flights / IT packages it simply was not worth the hassle operation-wise. However, issues like crew-positioning, maintenance ec. are less of an issue in a smaller country like Belgium (although one might also argue that in a smaller country there is also less incentive for customers to pay more to fly locally).