but there is rumor going on that there will be a real official licence to exchanges soon
Do you have a source for this? I'm not sure if things have changed since (this is from November 2, 2019), but Binance's CEO and other people based in the PRC debunked a photo which some people claim to be an official crypto exchange license:
On Oct. 30, an analyst claimed that a photograph of a cryptocurrency trading license issued by the Chinese government has leaked, indicating that crypto exchanges are allowed to operate within China.
However, Zhao and other investors based in China including Primitive Crypto founder Dovey Wan said that it is a basic generic business license containing the phrase “trading services” and that it does not represent a crypto trading license for local companies.
Considering the risk of capital flight and China's shaky position at the moment, I don't think they'll be allowing exchanges to operate freely and legally anytime soon.