I thought this was a bit of marketing genius on Porsche's part to capture some media attention. I saw a lot of headlines that read "New Porsche charges twice as fast as a Tesla".
Of course there are two caveats: (1) the new Porsche doesn't quite exist yet, but also (2) I think Tesla could fairly easily respond with the same charge time.
As I understand it, Superchargers skip the Tesla's onboard chargers (that normally do AC to DC conversion) and use their own array of chargers working in parallel to deliver direct current right to the battery as fast as it can take it.
So it feels like Tesla could provide 800V chargers with little to no modification needed to the cars. Does that sound right? I know they've been experimenting with higher voltage chargers.