Please remember they are a union shop with a seniority list of pilots there, and I have to believe many FO's are in line before you. That should help define what quick means. I personally would be asking this question if I interviewed there. Also, even if you get dumped into the left seat pretty quick, every time one of them upgrades, you get bumped down, and could be changing bases like crazy or even downgraded. Steet hire captain is a risk at ANY regional, it can work out, but it can blow up also.
All food for thought when making a decision.