I hope another airline comes in and replaces Monarch and the slots are not absorbed by the big existing carriers based at LTN... While I appreciate the airline had a far smaller presence at the airport, that compared to other carriers, I think the airport needs to try and continue to diversify its portfolio as much as possible, and try not to be so reliant on on the likes of easyJet and Wizz...
The only actual routes lost is Gibraltar, Dalaman (think TOM might operate it as a charter route) and Ovda, and just shows the competition Monarch were up against, and this is just at Luton! Will be good to see Gibraltar and Dalaman brought back, but not sure if Ovda brings much value?
Im not sure we'll see easyJet adding much additional frequency to the old overlapping routes, as this just dilutes the current fares on these routes and frequencies might only get added closer to the start of Summer 2018, if and when existing flights get booked up.
Im not too sure how realistic it is another carrier will expand or open a new base at Luton, would be great to see Vueling grow, but not too convinced of that either, as it has remained static for the past year or two.