NACS is just the standard CCS protocol shoved in the objectively better a Tesla plug, and part of making it a standard is the requirement of opening the design for everyone to use. So while the plug is from Tesla, they actually were the ones that switched to the CCS protocol first and dropped their own proprietary system, which is how they were able to open the Supercharger network to other cars in the first place.

And that’s also why NACS is backwards compatible with all current EV chargers that already exist with a simple adapter - either by the driver, or by swapping the cable.