I don't think it's a blow to WBS, don't get me wrong, Hynes is a great coach but we've seen coaches come and go from the team. 5 current head coaches were there. Therrien, Yeo, Bylsma, Richards, Hynes.
Botterill was on the staff for most of those hires. I'm sure he will lead the coaching search (he is the GM of Wilkes Barre IIRC).
I have 0 doubts in my mind about the new WBS head coach, they'll find someone. I mentioned Todd Nelson or Dallas Eakins as guys who have already coached in the AHL. There are CHL, USHL, and NCAA coaches out there that could be looking for a promotion.