NACS, which is essentially the Tesla charger, was made available to other car manufacturers at no cost already, in 2022. Due to a few reasons, among them the existence of Tesla superchargers already deployed, a lot of companies have adopted this as their charger for newer cars.
Even if Tesla went down completely, their charger is already open, so nah I don't expect any changes based on this.
Yeah I'm kinda surprised they made it open, to be honest. But they did, and its in a way that can't be retracted, so nothing depends on their continuing good behavior.
Also, I think Tesla saw the way the wind was blowing on standardization. Eventually, the DOT will enforce a standard plug, and if it's not YOURS, suddenly you have to either remanufacture the cars you're making, or otherwise refit them to work with the new standard.
A requirement for them to receive $7.5 billion in government funding for charger construction was for them to allow other cars to charge on their network, which required opening the standard.