I can’t imagine that Jenner is putting himself through the physical pain and public ridicule of all this on a whim - presumably he’s a deeply unhappy person and I hope he finds some happiness in his life. I would have thought that simply getting away from the Kardashians would have done it, but apparently that leaves some permanent scars, as Lamar Odom also seems to demonstrate.
I don’t think trans people change their genitals because of the loss of sensation. They don’t seem to do that any more. So she will be a girl with extra bits.