The ace in the hole for Hong Kong is that Beijing wants to unify with Taiwan as well and is promoting their relationship with Hong Kong as a possible model for how that might work. They want to demonstrate to Taiwan that they could reunify and Taiwan could still retain a degree of autonomy.
Beijing agreed to stay hands-off Hong Kong until 2047, but that doesn't necessarily mean the entire judicial, legal and political system in Hong Kong will become null and void overnight. In principle of course Beijing will be able to do whatever they like, but it seems at leas plausible that they will incrementally re-form the system in HK to their liking over time rathe than in one blow. In fact things like the extradition bill, which you can bet was at least reviewed and approved by Beijing if not dictated by them, is an attempt to start that process now through indirect means.
Ideally for Beijing, such indirect means would be the only means necessary even after 20147. Why impose change if you can present it as driven by HK legislators themselves?
Beijing agreed to stay hands-off Hong Kong until 2047, but that doesn't necessarily mean the entire judicial, legal and political system in Hong Kong will become null and void overnight. In principle of course Beijing will be able to do whatever they like, but it seems at leas plausible that they will incrementally re-form the system in HK to their liking over time rathe than in one blow. In fact things like the extradition bill, which you can bet was at least reviewed and approved by Beijing if not dictated by them, is an attempt to start that process now through indirect means.
Ideally for Beijing, such indirect means would be the only means necessary even after 20147. Why impose change if you can present it as driven by HK legislators themselves?