The Jet2 expansion can only be a good thing here; they're essentially picking up where Monarch left off, even if package holidays were only 5%of ZB's business.
They weren't afraid to take on STN with the colossal Ryanair programme and an 'underserved' package holiday market so presumably they like a good challenge. This setup from Thomson/Thomas Cook, combined with Jet2's 8 based operation from next summer... Should be a very interesting one indeed