It would seem so at first glance and if you just extend the upper and lower control arms to their instant centers then yes, this point is lower. However, to find the roll center you also need to project the control arm instant centers through the tire contact center line. It is in this axis where the roll center is located and goes up as spindle height goes up. This is also where wheel backspace can impact geometry as well since the tire center line moves more with backspacing than the spindle height effects things.
If you have lowered your car by turning the torsion bars down, this relocation is a good thing as it will reduce the need for stiffer t or s-bars to achieve the same roll resistance.
Another thing I forgot is the late BFJM spindle also has more axis inclination than an A spindle, so the steering return to center action is better as well.
