Adding on to this, ex-T knew all about some things ex-MC did for me that she didn't approve of (like talking to me on the phone for 30 minutes, not charging me for it). They worked in the same practice--he was actually an owner. And, to my knowledge, she never said anything to him about it (she said she only would have if I had said it was OK, which I didn't). And current T knows all about things ex-MC did. He knows him and they used to work together, too (current T has a solo practice now). But he's never taken any sort of action either, not that I would have wanted or expected him to. (Though they used to consult with each other on clients at times, and current T recently said that he hadn't talked to ex-MC in a very long time, so maybe what I shared led him to sort of distance himself from him).

So I do think it would be OK to share some things with the new T.