They always had a supercharger there, in Service, as far back as early June when I took my car in for service. It was available to owners in an emergency (if one knew about it, that is

) as per my service advisor.
They are making a true public facility available now, it seems. Remains to be seen if it'll not get 'abused' by Bay Area locals. Fremont's no more than 30 miles away from most Model S owner hotspots in the area.