Although I have no specific knowledge on this topic, I'd be willing to bet that those F.O's who are leaving are going to other regional airlines that offer higher pay for their F.O.'s *AND* Captains.

Places like Air Wisconsin, Compass, Endeavor, GoJet, Horizon, Republic, SkyWest, or TransStates. They ALL offer better pay and benefits for First Officers and Captains,....... without gimmicky bonus schemes,...... that can be taken away any time management wants to take them away!