It has nothing to do with realizing anything - its simply a matter of aircraft routing.
737s are being highly utilized out in the Pacific and with growing opportunities as the Japan market returns, so the desire is not to lose two daily on pmUA HKG
tag flying. So choice was to either upgauge the SIN
tag with US origin aircraft to free a 737.
Ultimately, there will be further shake outs in the intra-Pacific network, and I can see HKG
being dropped completely.