Well if the person who was fired acted anything like you, then they probably had it coming. Just because you don't agree, repeatedly misgendering someone is harassment. You do not get fired for using the wrong pronoun. You get fired for making a big deal about something minor, creating a hostile work environment, and going off an offensive rant. It is real simple, if Johnny wants to go by Jane, call Johnny Jane and keep your opinions on their life choices to yourself.