You are asking good questions.
Perhaps in meeting her and envisioning a relationship with her, and seeing how his feelings for you haven't changed, he has realized that you having another relationship face-to-face is not the threat he once thought it would be. And Hubs has seen you honor your agreements and knows you can be trusted.
I commend you for putting up with such severe restrictions on the relationship you have with your OSO for so long (I personally could not have a totally online relationship), but it does sound like the right time for renegotiation. Keep talking about it. I see no reason why you cannot gently voice the same concerns to him that you have expressed here. Poly works really well when there is full transparency.
After you get a few more responses, you can invite him to read the thread and add his perspective.