A little bit of context is required:
A proper democracy would be great, but it's not like Hong Kong had any democracy at all before the UK & China agreed on a handover framework (naturally, Hong Kongers didn't get any say in those terms, either).
This little fact also rather destroys the assumption of a link between free markets, economic success and representative government. Because Hong Kong was an economic success way before there was any representative government here. Same goes for Taiwan. Although in Hong Kong, not only could you not vote for them, a lot of the government couldn't even speak, read or write Chinese then - very representative, Not!
So I do find myself wondering what it is you expect China to learn from HK?
Free Enterprise was introduced by Deng Xiaoping years before China got Hong Kong back, so it's not that.
China actually helped introduce democracy to Hong Kong, so it can't really be that either - Hong Kong knows next to nothing about democracy: we've only had political parties for 10 years. Even China beats that!
So as it's not democracy or free enterprise - what do we have that China can learn?