as far as i know, ib in hk normally go to top US business schoos or LBS/Insead for 'mass' recruitment. I don't think HK MBAs have more opportunities even if they are in HK.
I am not in HK but many IB recruit MBA in US/EU directly for their HK office. In addition, there is HK trek that major US/EU business schools go to HK to meet IBs in Dec. I know many non-HK MBA join IB in HK.
I also met exchange students from HK MBA and they told me they don't have many opportunities to join IB.