I asked in HKG this week and they said "Late 2018"

Thinking about it - right now SFO-HKG and ORD-HKG has GF, but SFO-HKG is getting replaced first by 100% Polaris 777-300

that leave 8 GF seats on the ORD-HKG as the SOLE reason to keep the GF lounge around for over a YEAR, instead of closing it and starting to transform it into a Polaris lounge. That seems like a huge waste to me, but maybe i am just missing something.