Lol, what?! He's talking about view frustrum culling. That already happens and has happened for a very long time. You don't render the things you don't see on screen.
Edit: I'm assuming he's confusing that with keeping things outside the players view in memory. Games typically divide the game world into chunks and load them as needed, so the things you don't see are still in memory, so if you turn around they're already in RAM and ready to be rendered. There could be a change here, though I'm very curious of the limits of streaming per frame because of latency. They'd have to have latency to ssd in the same ballpark as latency to ram for it to be totally seamless.