This guy didn't try to forbid LT from talking about him at all - it sounds more like he is trying to get LT to focus on her problems rather than her therapists. LT doesn't have to do so, but it does seem like a great deal of time is focused on the the old therapists or the new therapists rather than whatever LT wants in her own life.
I also think he has a point about what you do with with therapists. In my opinion, the pattern has been done with the female therapist (on that one the marriage counselor was the hero), then he set a boundary and so this male therapist became the hero, and then he set a boundary and LT went to the woman who is being interpreted as agreeing with LT (she may or may not be - but to me - that is not the point). I understand why he thinks the behavior was manipulative - it might be unconscious, but I would read as manipulative and controlling too. I understand why the guy said he could never assure enough - it always lead to wanting more. Finding a new therapist is not a big deal, I don't think, but the pattern as to what sends you out looking for a new one, to me, seems the same.