The digital yuan might replace Bitcoin and the US dollar,but only inside the territory under the jurisdiction of the Chinese government.It's pretty obvious that the Chinese government will force the people and businesses in China to use this digital currency and dump other currencies.I simply can't see this currency getting outside the borders of China and becoming a global currency.
Meanwhile,the authorities in China might gather control over the Bitcoin mining facilities and try to manipulate Bitcoin.Many people say that this is impossible,but the risk remains.