I’m sure some people have made the mistake you are describing, but I doubt it’s only trans people who have made this mistake.
As a trans person, I would like to make my gender an aspect of my character, like most people get to do. I am more than just my gender, but my gender is a part of who I am.
It does feel good to be validated about my gender, but I’m not worried about people getting my pronouns wrong. I know it can be confusing and people don’t mean anything by it if they make a mistake. It’s hard to describe the intensity of the joy I felt once, when I was validated about my gender by another person. So, I will say it doesn’t surprise me if some people decide to express their gender a lot once they are finally able to.