I'm curious how much evidence you had to provide to show that you're truly living full-time, and who was requesting it, and when it needed to be done - say, a full year before surgery? Does half out (social but not work) count? I'm kind of in that boat, out to my friends and family but not at work, and the idea is still a titch unnerving, as these people won't see it coming at all. But it's them or me! I have the law and our company policy on my side, too.
As an aside I've read about people who've faked the whole thing, wishing to have surgery/hormones but to keep presenting as their gender assigned at birth for various reasons - personal, financial, because it's who they are, etc.