I don't know if we have ever really talked about this, but I'm sure my therapist would not be open to a friendship after therapy. For her and for me, protecting the work we've done together is paramount, and I could see where normal friendship ups and downs could really undermine the things we have worked through together.

As much as I like my therapist, I am not terribly interested in a friendship either, because I don't want to lose my ability to go back to her as a client when/if other things come up in my life after we've ended regular sessions. (Maybe if she retired I would feel differently, but I can't see her ever going further than semi-retirement unless circumstances dictate it.) There are plenty of people in the world who have the potential to be good friends but far fewer who have the potential to be good therapists for me.

That said, I think my T would be open to something like occasional email updates indefinitely. She knows I stayed in touch with my former T from the end of therapy until her eventual death ten years later. I don't know that my current T would become more chatty and casual like my former T did, but I think on some level she would appreciate maintaining the connection.