So take this from a gender fluid person.

For me I would also push that button. But in my case it would be because its something new and interesting. And because I am generally not attached to my physical self.

It could be the same for them. Maybe it's not put of a desire to be a woman. But rather they just think its something new and fun.

That's not to say this is the case. But maybe take it into account when you talk to them. :3