I don't know but I've read that document over a few times now and I don't see where it states that VSC is actually active in 4WD. It simply says that you can select between Normal and VSC Off modes. But it looks like these 2 modes refer more to the A-TRAC than anything else. It may be the way it's worded.
But the chart looks pretty clear that VSC is off in 4WD:
in fact it looks the same as the '07 in this regard:
