Billy comes off well here. He's the boss. He's trying to be delicate and as open as he can be here.
Certainly he probably didn't get out in front of the D'arcy issue and communicating with her as he should have early.
But we do have circumstantial evidence to believe that the reality is such that she's not equipped to be a full regular part of this. And there's no kind or objectively appropriate way to put that to someone.