There is absolutely no way that China will be able to take the control of Bitcoin in the future. It is totally against Bitcoin's nature first of all. Whatever China government tries to do, they won't be able to change this thing. When it comes to mining, I don't think most of Bitcoin will always continue to be mined in China. I actually expect the miners to choose another country to mine most of Bitcoin in the future. Because it won't be sensible for them to always continue there as China is fully against Bitcoin.