Here is what you drew but with some numbers attached. What you're saying, yes is correct if camber curve is ignored and an I beam is used, but your plunge frame of reference though isn't applicable to how a Short/Long arm system works, or even a trailing arm system. What you're alluding to is...
If a tie rod is lost in a conventional system, the upright will flop because of the caster and the need to lift or fall of the wheel depending on the direction you're trying to go.
In the virtual pivot system if a tie rod is lost the wheel will remain in the neutral position, straight or just...
Let me see if I can help clear up some of the details. Our shop has done all of the engineering on all of the Xtravel technology-based suspension kits. So, I know first-hand how the "sausage is made."