I'm not sure how that link posted, but the Chinese authorities have authorized Hong Kong CAD to continue to implement ICAO procedures. Hong Kong is NOT a state. Hong Kong CAD continues to operate autonomously from the mainland, although in the long run I'm sure everything will be integrated.
The Hong Kong licence is "issued in accordance with the provisions of Annex I to the Convention on International Civil Aviation signed on 7th December 1944". I believe that makes it "ICAO". Almost all pilots coming to Hong Kong would have an ICAO licence before they arrive anyway.
I think that you will find the CAD recognition of foreign licences in line with most states. By law you will need an licence issued by the state to operate aircraft registered to that state for commercial purposes, and most countries require some written and practical exams, plus logbooks. All very easy for a professional pilot.