The fact that their may be no availability between Hong Kong and China doesn't surprise me especially - it is just prior to the start of the Olympics afterall.

What surprised me is that searching for a first class award seat between HKG and PVG seemed to show plenty of availability on Dragon Air (as reported by CX's own award search form), even though the award seats aren't there, and in fact, first class may not even exist on many/most of these flights.