Nah, but for serious if I was looking for any kids show to introduce a trans female comfortably and with success, I would be looking at Star vs The Forces of Evil. A show which has diverse personalities for all its female characters - Jackie, Janna, Star, Ponyhead, Starfan 13. All of them are different, but they are all still girls. None of these characters are ever told to be more feminine or are called manly. Janna who literally says in the show, “I just hate contributing to gender stereotypes”.
If Marco were to identify as a trans girl in the show, they’d know not to make him any different than he is already. They already know that girls have different interests and looks and attitudes and everything. All they’d have to do is for Marco to say the words, “I don’t think I’m a boy” or “I’m a girl” and you’d believe it because that is what the show is about. Being a girl. Not wanting to fit into the standards people expect of you as a girl. Marco identifying as a girl fits into the show so well and fits into everything it is trying to represent.