If it hasn't been enough incentive to stop SO's and junior FO's resigning now, reducing the pay is hardly going to improve retention for their replacements.
And, I haven't met any TT SO's who've been surprised at the cost of living in HKG. They did their research. What has changed for some, is companies with terms and conditions that suit them better have started recruiting since they moved to CX. Quite a few now have offers and are resigning.