In MA, would it be legal for a licensed group therapist to disclose to other group therapy members that one of their members hasn't paid her group therapy bill with him for over a year?

My group therapist regularly shares that one member hasn't paid her bill in over a year, and makes it part of the 'therapy process.' He wrote her an email about it while she skipped group, and read it to the whole group aloud.

Is this a HIPAA violation or not exactly?