What will we be using, Chinese Yuan?
Might be cool if we will be using the Japanese Yen instead of that Chinese Yuan.
But I doubt everyone would be happy to accept that as there are still some currencies out there that has much acceptable due to its high value, and yes one of them is EURO.
The question is, what do you mean by crash?
He might mean that FIAT will be unusable due to bitcoins having a strong number of value like that of GOLD. (maybe?)