Back on topic ....
The HK$ will eventually decouple from the US$. Later rather than sooner, in my view. Maybe 3 to 5 years away.
When it does decouple the HK$ will rise.
It will then quite likely be re-linked to another currency or basket of currencies. Possibly with a longer piece of elastic.
If you have a HK$ salary you will benefit. Prices of imported stuff will fall.