Early Admission Scheme

I have never heard of such a case in Hong Kong. Deferred entry is not a common practice in Hong Kong.
I think this is not recommended by the universities in Hong Kong. The whole selling point of the "Early Admissions Scheme" is that people can get into uni a year earlier than most. It's not an "unconditional offer" scheme.
(I also wish there was an "unconditional offer" scheme, completing F.7 is better in a way -- you're more mature and you've learnt all the stuff in the A levels + got a result)

You can try phoning up CU / HKU to ask anyway.

My opinion is, if you get into something that would really be your first choice no matter what, such as the medic courses, just accept it -- they say that EAS students do as well as normal JUPAS intake students. (With 9A*'s it's probably lucky for you if you got in medic-- so I'd say accept it.) If you don't, then try to explore the option of deferred entry.