It's a Good Thing it Just Needs to be Dealt With
No company has complained about having too much business, but it is a challenge to keep up with.
The same should hold true for Hong Kong. The solution will come from engineering a smarter, more efficient and higher density city. Buildings can be built taller, transportation denser, etc... Build elevated monorails connecting buildings on upper floors if needed. Think futuristic solutions and the city will be able to comfortably grow.
The economics of high density are unmatched. Reducing growth is not the solution, dealing with it and supporting it is.