For someone joining now would it would be unreasonable to expect a command inside of 7 years ( manager's words ).
This would be subject to an expansion by Cathay that isn't guarranteed.
Something else not factored here is that in that time frame there will be a lot of locals ready for upgrading too.
Is it fair to say command prospects at Dragonair bleak and uncertain?
You will go backwards on a KA first officers wage living in Hong Kong for a long period. This with consideration to the resistance to any much needed payrise and what you get paid now is what they will want to pay you in a decade!