I dno how he knew. But he had an incredible mind. So I'm not surprised he knew.
Discussion
I wonder whether he was following the cypherpunk stuff to any degree.
Well I think he was. I think his grandson told him about BTC and similar projects. Possibly his soon too. Both are anarchists I believe. But I don't know if that would have happened after this video or before.
But maybe he just knew the central banks would never give up their power. And had faith in human ingenuity and technology.