Northern, Ryanair have never operated from Exeter, which is and has been the base airport for Flybe (and all its previous guises).
They certainly did operate from Blackpool, but pulled out early in 2009 citing Blackpool Airport's introduction of a £10 per person development fee as the reason. As BB were 95% owners of the airport at the time, this must've been their idea. Whether BB intend to introduce such a fee at CODA, and whether DCC as owners would allow this, remains to be seen.