Bee, abusers pull this stunt all the time.
There are only two possibilities: the therapist is not qualified to work with abusers, most aren’t, and has an ethical obligation to refer him to someone with the requisite skills. Few therapists know how to and are willing to work with abusers. It’s a safe bet that he has not told her much of the truth.
Or, whoever called you is a fake.
He wants to change, does he? A great start would be for him to start showing some respect for your boundaries. And by not having an incompetent or make believe therapist ambush you.
She’s not his representative, she is way out of bounds.
A legit therapist would want you two to separate while he’s in treatment. When and if you decided to return to him would be totally your decision, on your timetable.
He’s had a narcissistic injury—you dumped him. He’s scrambling for a way to get his power back. But, this veneer of wanting to be different is very thin. His low frustration tolerance will win out when you don’t fold. You’ll get to experience plenty of rage when the veneer cracks.
Your wisest course is to do nothing. Block his number. Why have you not done that yet? No talking/texting. It would be a festival of gaslighting. And you would be seriously set back in your recovery.
Even if he really was in therapy and not just using it as a ploy to get you back under his control, a few weeks of seeing a therapist doesn’t fix anything. If he’s sincere (about as likely as me waking up four inches taller tomorrow), he has a very long and difficult slog.
After 12 months of respecting your rights, your boundaries, by leaving you the hell alone, you can revisit the issue. I’m not worried. It’s not going to happen.
When he finally gets tired of beating his head against a brick wall, he will switch his energy over to finding and grooming your replacement. These guys are never really done with their victims, however. So brace yourself for his resurfacing just when you finally start feeling completely free of him.
These guys are so predictable. Always keep four square in your mind what this guy is about, he has a different purpose for being in a relationship than you do. All that he truly cares about: power and control.
Also know that guys who are wired like your ex cannot stand being alone. They just can’t handle it. He’s lost without a victim. He doesn’t enjoy the pleasure of his company any more that the rest of us.