I can't see BE returning any time soon. If the IOM & JER routes were seen by them as viable from LTN then they surely wouldn't have dropped them & could have found a way to integrate them into a W pattern originating from somewhere like BHX or SOU.
I struggle to see why these routes can't be made to work by another operator. JER has been a fixture of the summer schedule for as long as I can remember. Even if a weekend only, summer service was flown like in the old BD days there must surely still be a market for it (same with GCI)?
As for IOM, does BA from LCY & EZY from LGW really saturate the market in the London area?