Not saying it's right but it's common for players to leave when a coach does. I'll also point out that Josh Wiliams, Tavian Dunn-Martin, and Ty Dalton are the only one's that have formally said they're leaving. Williams isn't going with him (I think there's a better chance of him returning to UA than going there - he wasn't happy with KD). Dalton doesn't seem like an A10-quality player, so I'm not sure where he lands. TDM is extremely loyal to the coaches because they were his only D1 offer.
As for the unsigned recruits, you see this with almost every coaching change. I'll note that zero of them signed with Duquesne to this point, so let's see what happens.