FlyBe are really stuck between a rock and a hard place, aren't they?
Aer Arran's pullout means there are now some 5000 of their former pax wanting to go to/from London who have no choice but to use FlyBe. Does FlyBe have the capacity to carry them? Dunno, but when EuroManx closed it became next to impossible to get seats on some rotations, even at full price. The Friday afternoon/evening rotations were a particular problem. And because the loads will be higher so will the ticket price. So the Manx public will no doubt become vocal in their criticism, and the politico's will jump on the bandwagon and demand FlyBe provide more capacity.
But these are the same public and politico's who have encouraged Easyjet to start on the LGW route in October. Even if FlyBe could find an additional airframe and a pair of LGW slots, why on earth should they bother?
Of course they might deploy an E195, but there isn't one available, and the locally based crews aren't (I assume) qualified to fly it. Maybe they could use one to operate the mid morning/lunchtime rotation from LGW, and use the local Q400 to replace whatever the E195 was doing before. But that would screw up the rostering.
It will be unfortunate to see FlyBe's reputation suffer during this summer at a time when they need all the goodwill they can get to deal with the soon to arrive Easyjet competition.