The fact that Air Slovakia have done nothing much for years is no guide to the future. It's a whole new world now in eastern Europe. This is a time of exceptional opportunity for any state that has an advantageous geographical position, ethnic traffic flows that can be captured on a sixth-freedom basis, and cheap planes.
In terms of credibility, I'd rate it 90%. BIA have heard too much flannel to give it their endorsement without a very high level of confidence. My guess is that it'll happen.