Well. I believe it would make sense the government of China or some politicians there to hold Bitcoin in some degree.
But in my opinion, China is already in a position where they have much power on the west by holding other kinds of assets and mineral resources which are completely unrelated to Bitcoin or cryptocurrency. For example, we could take a look at the Chinese holdings of United States debt.
Source: In the image.
If China truly wanted to damage the economy of the United States and also of her allies, then they could easily do so by dumping all those debt bonds into the market and make the economy of the west to suffer.
Viewing how geopolitics work, to me it would seem that one needs more than just a bunch of Bitcoin at high prices to literally take over complete international markets. The United States could pass laws to reduce the influence of the Chinese monopoly in manufacturing, as Donald Trump intended, for example.