Do they really need modified hardware to keep track of the amount of power? And what exactly would that hardware do?
One of a charger's main jobs is to adjust the power into the battery on the fly (and it's why we constantly tell people that the box on their garage wall is an EVSE, not a charger). The supercharger already knows the information since it's a fundamental job requirement. Tracking it on a per car basis seems like nothing more than a software enhancement to accumulate the the data and report it.
I would believe though that they need updated hardware to do the communication. NACS cars speak the CCS protocol, not the proprietary TPC protocol. Your Tesla needs the CCS enabled hardware to charge at a CCS site, so why wouldn't the charger need that as well? I thought that V3 chargers already had that, but maybe they merely have an upgrade path that the V2 chargers do not have.