I think you're a bit cynical about Kaitlin Jenner, but I won't deny that the media has used the celebrities you mentioned for its own purposes.

And crossing stereotypes most certainly doesn't suddenly make you transgender. Though perhaps when dealing specifically with clothes, at one point perhaps it makes you a "cross-dresser", which used to be used to refer to women as well, or "drag queen". Wanting to play with Barbie dolls or even dress up like a girl doesn't make you transgender though, any more than it makes you gay.

The reason why so many more males are transgender though might have to do with the greater pressure they have to conform to stereotypes that they may find impossible to conform to though.

Sadly, some of these people may transition, and still feel like they are not themselves, because frankly, society is abusive, and they have basically been gas lit.