I would be slightly taken aback by it. The thing that would bother me most is if he wouldn't respond when I asked about it. My husband definitely has a business personality and a personal personality, but I can't imagine his business personality not letting on in any way that he has a family. Oh, and he doesn't wear a ring either.
Some men can be clueless. If the OP only mentioned it "in passing" or "casually", he may not have realized it was a matter of concern. You have to be very clear.
Sometimes I have to actually tap my husband on the top of his head to get him to realize I'm speaking to him. He'll be focussed on a game of chess, or reading the newspaper, and even though he's saying "Uh, huh," he's not actually hearing me.
When I want him to really HEAR me, then I sit down in front of him, get eye contact, and say it nice and plain. "Honey, when I went to your work site yesterday, no one knew you had a wife! This really bothers me."
Sometimes if he's puttering around, doing a million things, I actually have to grab him and make him look at me.
And sometimes, if it's something complicated that I need him to pay attention to, then I tell him I want him to come and walk the dog with me. (Well, sometimes I just do that for fun, too. It's nice to have company!) When we're walking the dog, I've got him all to myself and there's no distractions. That's when we have our best heart-to-hearts.
He's an extremely smart man, but he's also your classic MAN. He doesn't communicate the same way I do.