China is the largest creditor of dollars, the Communist Party won't watch the process of dollars dead
China can offload its Dollars and when the USD looses most its value in a short amount of time, the USD holdings of China will lose its value but China will be the biggest beneficiary of the dismiss of the USD because the Yuan will appreciate compared to the USD and the Chinese will enjoy an increase in their standard of livings : they will consume more
China becomes the second largest economy following by the USA in terms of GDP. The increasing number of trades are conducted with yuan. The USA is falling in the steep hole of debt and will lag behind China or other countries no more than 10 years (personal opinion, no offence). Whether bitcoin will play the role of currency will depend on the policy of China and the USA.
I don't think increasing number of trades are conducted with yuan. Until China opens up its capital markets, foreign investors find little use for yuan,
The Communist Party in China is opening up the Yuan to the markets