The company is desperate to fill the HKG and CGN domiciles, but any new hire is not at all required to accept one of those assignments. You can say "Thanks for the job offer, I will wait for a MEM class date."

You are still hired, and will be placed in the first MEM class that opens. Right now they are saying they need people in the A300 in MEM, but they will need 757, 767 and MD-11 people as well.

Don't bite off on two years in HKG or CGN unless you are sure that you can really swing it on first year pay.