Allan - that's complete tosh. Stobart applied for slots at Gatwick and withheld the destination for those slots when they did so. They had also talked about expansion plans at BHD around the same time. You - or whoever told you this - have added 2+2 and most probably got 5. They have never signalled flying BHD-LGW and it's an idea of someone's own creation. I'd heard that their LGW slot bid was for the Newquay PSO but I can't say for sure if that's true or not, so I won't pretend to know.
The franchise position is that any route has to be agreed by Aer Lingus to be a franchise service which is the same across pretty much every franchise. I understand they could not fly the E190s as Aer Lingus franchise aircraft but as they no longer have them, it's now irrelevant.