I have a son that loves ballet. He's 3 and loves to dance. I could beat him, because ballet is arbitrarily "girly, " or I could encourage him to do things he loves.
I am much more interested in him being a kind, well-rounded person than I am interested in him being someone else's stereotype of a man.
I kind of still dislike some of the even more nuanced discussion around gender because it's goal can still be to categorize. More precisely, but still occasionally hurtful. I would love for everyone to be happy as they are, undefined by anyone but themselves. I've known people who came through so many awful experiences, and some found comfort in the group acceptance of a new gender definition, but the ones I know who are happiest eventually shrug that off entirely and find full self-acceptance. It's so hard to do, and not everyone can, but gender acceptance is only a stepping stone in the path to self-acceptance.
Speaking from (my brothers experience) boys who dance and are good, get the girls (if they are into girls). Fuck the ones who judge, I have three boys, let him enjoy what he likes.
male dance kid here - ballroom or other partner dance is actually a good start for the quite young as it's more about footwork and you have a partner to help guide you.