OK, I get it now!
I couldn't see the steering box that is attached to the rack itself!
Thanks Butch, for the photo!
While this setup may work for 2WD owners, it is highly doubtful that W trucks could use a gear box that moves with the axle. W's would require a cross-member and that could result in serious bump steer.
There is no bumps steer with the D setup, but that slip joint would present serious design hurdles for it to work on a 12" axle articulation that the W trucks might experience when off road.