Since the Rift S is a single screen I thought they were doing IPD in software. Of course that assumes the lens for each eye can accommodate the settings.
They dropped the required FPS to 80 even though with the CV1 they said 90 was required for good VR.
I see it as a cheaper to build CV1. I'm pretty happy with my CV1. I expect real improvements in VR will have to wait for much more powerful CPU's and GPU's.