I believe a service about the exchange provider has avoided china for their operation office.
If they want targeting the Chinese customer, they will provide a language Chinese from their service. Most of the exchange open their service with regulation "Hongkong" or "Singpore", they don't want to take the risk with the regulation went open a exchange at cina.
Yes, China is not allowed to open an exchange for the time being, but it does not hinder Chinese transactions. This is why the large exchanges are all Chinese and support Chinese well.
