I'm sorry you weren't informed and can definitely relate. About 8 years ago, I saw a marriage counselor (ex-MC), to whom I was very attached. He shared a fair amount about his life from the first day we met him, including about the baseball team he roots for (same as H) and about his daughter and son. Also about his own anxiety issues and some childhood struggles (this was over time). Over time, I came to learn, from overhearing a call at the receptionist's, that he had someone living in his home who needed 24-hour care (he was late because the home health worker hadn't yet arrived). My T at the time, let's call her "ex-T," worked in the same office and confirmed this to be the case.

I figured maybe it was an aging parent. Then, he shared a story about his wife, and his odd response to a question I asked made me realize it was likely her. When I asked ex-T, she teared up, so I knew my guess was right. I asked him, he confirmed, but didn't give much information other than, in answer to my question, that it was a more "chronic" vs. "terminal" condition. There was a stretch where he had to cancel frequently with short notice. He also said to me at one point (in a phone call--long story) that he might need to take some time off soon. I wondered if she was dying.

He canceled just after Christmas, and I asked ex-T about it. She said, "He absolutely had to take that day off" and looked teary-eyed. I went home and googled her name and "obituary." She'd passed away about a week before (she was late 40s, so quite young). My husband emailed him to let him know we knew and send condolences.

The next session we had, he listed her long list of maladies throughout her life. The part that is relevant to your post is that I asked him if he'd have told us she'd passed had we not figured it out. He said he wouldn't have. I asked, "What if I asked how she was doing?" He replied, "I'd have said something like, 'things are OK.'" It hit me hard, realizing that the relationship wasn't as close as it felt, as he wouldn't have even shared that his spouse had died (even if we asked). I feel like the relationship wasn't the same for me after that.

I'd definitely talk to your T about it. It helped a bit talking to my ex-T (at the time), and I also talked to ex-MC about it (but probably should have let him be on the topic for a bit, but: see attachment/paternal transference).

Sorry for the novel! TLDR: My ex-marriage counselor's wife passed away, and he wouldn't have told us about it had we not figured it out. Even though he tended to disclose quite a lot of personal stuff.