I read the SAE Press Release, and since I'm not a Standards guy, I am confused as to what they're saying they're going to do when going through the process to "standardize" the NACS connector...
Despite the fact that NACS is an acronym for "North American Charging Standard," NACS is not a true standard by most definitions. Most standards are released by industry standards organizations, like SAE, IEEE, ISO, etc. They're created by multiple companies, universities, governments, and other interested bodies who come together to decide how things should be done. NACS, by contrast, was created by Tesla and for Tesla, with (AFAIK) no input from anybody else. It was, at best, a de facto standard, which is something that one company invents and others copy. SAE is simply saying that they'll adopt the NACS specification and release their own version, to be controlled by them. They'll probably start with Tesla's current specification and tweak a few things. They might expand the section on V2X charging, for instance, or add limitations or verbiage on acceptable voltages and amperages.
I noticed they used the phrase "the new SAE NACS connector", which is very interesting...
That'll be the new SAE version of NACS. Presumably it'll be very close to Tesla's version, since Tesla already has a huge installed base. They can't change the overall size of the adapter, for instance, or it'd become something completely new that would be incompatible with current Tesla vehicles and Superchargers, and that would defeat the whole purpose of the exercise, at least from the point of view of Ford, GM, Rivian, and Volvo -- giving their cars access to existing Superchargers. Remember, those companies have considerable sway with SAE, so those companies (plus Tesla and various others) will be steering the process so as to meet the overall industry needs.
What does this mean for the J1772 standard?
To quote Betelgeuse (the character from the movie, not the hot ball of gas), it's "dead, dead, deadski."
Well, maybe not quite as soon as CCS. J1772 has been used, AFAIK, by every plug-in hybrid ever sold in North America, so there's a significantly larger installed base of J1772 vehicles than of CCS vehicles. There's no Level 1 or Level 2 NACS equivalent to the Supercharger network to entice manufacturers to switch, either. (Yes, there are Tesla Wall Connectors at hotels and a few restaurants, but those aren't nearly as compelling as Superchargers are for BEVs.) Thus, it's not clear to me if legacy automakers will be switching their PHEVs to use NACS, or sticking with J1772. Thus, we could see J1772 linger for quite a while longer than CCS. OTOH, if legacy automakers do start using NACS on their PHEVs, then J1772 will fade in a few years, just as CCS will, but I'd expect it will linger longer because of the bigger installed base. Whatever the case, J1772 is on the path to extinction. If nothing else, eventually even PHEVs will go away and be replaced with BEVs.