I wonder, obviously you know him best. But just based on what you've said here, I wonder if his "gender blind" comments were more meant to be reassuring that he still sees you as his friend, just as he always has. That he's not going to treat you differently because you're trans. In his mind that could be what a good friend does. That they are friends with the PERSON first, not their outward appearance. That the friendship is based on other things than gender.

Does this man have other female friends? Or is his friend circle mainly men, and you?

Because maybe it could be "he still treats you like one of his friends" rather than a man per se.

I don't treat my friends like boys or girls. They're my friends and I treat them as individuals. Yes I know their gender and I affirm their gender. But I don't think that necessitates being treated differently based on gender.

I don't have special things I would only tell "other women". I share things with friends based on trust and how well I know them, and their specific boundaries.

If my best male friend came out as a trans woman, I would affirm her new pronouns and identity. But I wouldn't start reducing what I said to "her" vs "him". If I started not telling my friend something I would have told them before, because they came out as trans, imo that would be bigoted. That would be prejudicial. I'm friends with my bestie for his soul, and if he was a she then that would still be true.

And yeah that includes discussions of things like, sexual fantasies, embarrassing bodily functions etc. Because nothing is TMI in our friendship.