No, competing with the big boys at LHR is / was a daft idea. Flybe could and should have focused on routes with less, or no competition from airports well away from LHR. I suspect that is what they will do, and IF there is the opportunity to raise capital selling slots, given the depressed state of the industry presently, they'd be foolish not to flog them. However that doesn't make running an airline just for the objective of selling slots a business plan.
Flybe aren't going to be an airline with 10s of aircraft operating from hands full of bases any time soon, but that isn't to say they won't find a profitable niche and grow organically.