It will be interesting to see Miley Cirus about 10 or so years into the future after they've reached maturity. If they feel like a boy, in time I would think the desire to express that side would become stronger and the time will come for a transition to start. I wonder how strong this feeling is and where it will this lead them?
I agree with the comment above about Miley's cuteness and white factor being a hindrance if they in fact were to pursue a gender transition. People will be quick to NOT take them seriously, and will laugh, call them crazy, etc., and think all kinds of nonsense. The public has already done this. I speak from experience, since I've been going through this myself at my place of work over the past year when starting my own transition, having started as this very cute, pretty little feminine lady facade I had for so many years. Miley's in a much better position than most of us because of the money and privileged life factor. Still, I predict they will be met with many challenges down the road to being accepted and taken seriously as a trans man (assuming Miley pursues this path).