I know Flybe have some issues at the moment with fees at Gatwick but still unsure why they do not take on the Gatwick-Manchester route when BA suspend it from the end of March. It carries point to point traffic as well as some transfer traffic to BA/VS longhauls. 3 times daily with mix of EMB175/EMB195 may be viable especially with codeshares with BA/VS. Even a contract agreement with BA may be worth looking at like the London City-Isle of Man one BA has with Eastern.
I am also surprised that GIP do not seem too concerned about losing the link between two of England's largest cities. I understand they want to expand longhaul operations but losing potential transfer traffic from the regions does not strengthen their case.
V.