I'm reading the announcement differently. They are saying future non Teslas who adopt NACS can use the Tesla chargers. It doesn't say anything about current CCS cars being able to use Tesla charging.
Even after this move I don't see any way that the Tesla standard gains enough momentum to take over from CCS in the non-Tesla US EV market. If Tesla had done this in 2015 there's a chance it might have caught on globally. With the non-Tesla US EV market locked into CCS and growing rapidly (and Tesla itself already committed to CCS in Europe), it feels like the Tesla standard is doomed. (In fact today's move is actually sort of bad news, since it indicates that maybe Tesla hasn't quite accepted this reality.)
[1] https://electrek.co/2022/05/10/tesla-add-ccs-connectors-supe...
> NACS is the most common charging standard in North America: NACS vehicles outnumber CCS two-to-one, and Tesla's Supercharging network has 60% more NACS posts than all the CCS-equipped networks combined.
Yet, in your link it's complained about that the Supercharging network capacity is already strained. Bottom line is that the vast majority of the charging stations that will exist 10 years from now are still yet to be built.
Tesla may still be hoping for a regional break, as their standard wins in some geographies but not for others. This would be a loss for all of us all collectively.
Certainly feels like they should have known better. Past greed will leave them (and their customers) with a massive writeoff in the future if your prediction comes to pass.