Crypto is valuable but I don't think that it would be more valuable than gold. Remember it is only a technology and technology become obsolete in due time. We can see where it can outshine gold but I believe that it won't out last the valuability of gold. In short crypto can be more valuable than gold in certain point of history and diminish but gold will always remain valuable for eternity.
I think he was referring to the capitalization of cryptocurrencies and gold. Objectively, the capitalization of cryptocurrencies may well exceed the capitalization of gold, but this will definitely not happen in the next few years.