It is just a conspiracy theory so you need to you understand the reality that Bitcoin is not controlled by anyone at least with the current value 51 percentage of attack is not possible and the blockchain network of Bitcoin.
Of course, Bitcoin can never be controlled by any country including China itself. And bitcoin was made as an independent digital money thus it is clear that no one will ever have an authority or power to Bitcoin. This theory about China controlling bitcoin is all not true. Decentralized system can not be controlled, remember that.