Well, I'll believe it when I see it:
https://ew.com/movies/2020/01/02/kevin-feige-mcu-transgender-character/
During a Q&A at the New York Film Academy last week, Feige was asked about LGBTQ representation in future Marvel movies: "Are there any current plans on bringing more LGBTQ+ characters into the MCU, specifically the T — trans characters?"
"Yes, very soon," Feige responded. "In a movie we're shooting right now."
https://ew.com/movies/2020/01/02/kevin-feige-mcu-transgender-character/