There were these two people at the con; I'll call them "Gretchen" and "Dave". "Gretchen" is a friend of mine who is a transgender individual; she is biologically male, but prefers to be called by a feminine name and pronoun. (She has not had SRS.) "Dave" is also a friend of mine, and I think he's a really smart and funny guy; but he refuses to call "Gretchen" "she". He insisted to me that "Gretchen" is really a guy, and he's going to keep calling her "him", saying, "Pronouns are not opinions!"
Well, many years ago I might have agreed with "Dave", but now I have a broader view of the subject. What it comes down to is questions such as these: How fluid is identity? How fluid should it be allowed to be? Can gender be part of that fluidity? Is it okay for a person to control his/her own identity?
To the last question, I say yes, within reason. Obviously it's not okay for a person to pretend to be someone else for fraudulent purposes. But if someone wants to be known by a certain nickname, or a different pronoun, who does that hurt?
In furry fandom, almost everybody has a fursona. Online, I know people by their fursonas. When I meet them in person, I call them by their furry names instead of their real names. Why? Because that's how I know them. Why should I suddenly use a different name just because there isn't a computer between us? And why should the situation be any different if gender-bending is involved?
And with TG people, it's even deeper than that. The old-fashioned way to refer to a TG individual is "a woman trapped in a man's body" (or vice versa); there's more than a grain of truth to that. There are certain minor differences in the way men's and women's brains are wired up, and yes, it is possible for the gender of the brain to not match the gender of the body. So if a person wants to be called by a pronoun that doesn't match the bits, he or she is not doing it to annoy you, but to reflect his or her true inner personality. It is insulting to refuse to respect such wishes.
So yes, Dave, "pronouns are not opinions"! But I mean that in a different sense. Gretchen's pronoun is not subject to your opinion.