Possibly, but the devil is in the details.
I plan to look at these details when I reach 60 or so...
He certainly knew what he was talking about on this one among many other things. Smart man.
It did happen in other countries, and could happen in the US as well in the future.
Indeed, this strategy failed in a few countries, and it's not impossible that it would fail in the US (or the global stock index for that matter) as well. This is one of the motivations for diversifying into other things such as rental properties.