Correct me if I'm wrong but everything seems to be originating from this article that only talks about what people familiar with the matter said:

https://www.bloomberg.com/news/articles/2018-01-15/china-is-said-to-escalate-crackdown-on-cryptocurrency-trading

People familiar with the matter is all it says, no names or further description of them... It also says "China’s central bank didn’t immediately respond to a faxed request for comment."

That's all I know about the origins of the talks of China banning more. Do you know anything else ? Because this alone doesn't sound persuasive to me that such a thing may happen.