coach of Team A is upset at a moving screen set by player B1. After complaining to the official, he turns toward coach of Team A and says something like "if that is the way you are going to play, then we will ....."

My question is, if I hear it as an offical, do I "T" the coach, or can I eject for threating the opposing coach.

If you feel it warrants a T, fine. I wouldn't eject on this, though. It's not a personal threat toward the coach.
My suggestion is to watch for the moving screens and call it if they generate illegal contact. (remembering that moving screens are legal if there's no contact)