PS,
The company does not need to sponsor the dependant because you (not the company) are responsible for your dependant. The immigration evaluates your ability to support the dependant and usually gives the Visa without any problems.
The new rule is that the dependants cannot work on that visa. They will have to get their jobs and the company will have to sponsor them, just like any other job related visa.
I'd definately recommend emailing immigration and asking them for more info.
http://www.info.gov.hk/immd
They are very responsive.