Some clients like and need more self-disclosure, and some need less. If you want to know, and he is willing to tell you, then it is fine for him to tell you. I appreciate my T because she does tell me the basics of what is going on with her, like when she was depressed because her cat died. I wish that she would tell me more about her life, but I guess she knows where to draw that line. Since I know that I have problems with boundaries, I think it will be a struggle for me to know how much to use self-disclosure with my own clients.

Alex, I think that you should tell your T what you know about him if it is something that you want to talk about, or if it affects how you feel about him. It is okay for you to know, and you have a right to information that is public knowledge. It's fine to talk about it too. Feelings in therapy are very important, no matter what they are about.