According to the article, the CEO said that " but I think bitcoin could surpass the dollar as reserve currency within 10-15 years." Bitcoin will surpass it's use against the dollar. It will be great if the majority of the people around the world use Bitcoin. If that happens, I think that will be the start of the ruling of Bitcoin. The wallet will be a reserve, instead of having banks to be used for storing your money.
Then at that time in the future, Bitcoin has surpassed the dollar.
That is too optimistic. It will be unlikely the majority of the people around the world use Bitcoin.
Bitcoin could do it within 10-15 years, adopted by majority of the people and no need apocalypse scenario due to people should notice existence of bitcoin as worldwide currency which has many advantages and highest exchange rate. Surpass maybe but I don't think bitcoin will replace dollar as it a state currency and consider as international most acceptable too, bitcoin may get along others currencies.