Okay, so here's my take on trans people who might not be in a big hurry to come out as trans or advertise the fact that they weren't born with a body that matches their gender: They've already spent their entire lives trapped inside that body, answering to pronouns they don't associate with and playing gender roles that don't make sense to them. So yeah. I can totally understand why they might not personally feel like giving us a detailed backstory of their transition, especially since the whole point of transitioning is to merely be the person they were the whole time.
Kylie is a girl doing hot girl shit. That's all we need to know.