toxicTom: a) Maybe Tencent put pressure on Epic who in turn put pressure on GOG (Epic store in Galaxy) or something like that, and/or
b) GOG in all their glorious competence we've all experienced really somehow didn't know about the controversy surrounding this game in China and when after the announcement the first million complaints came in someone quickly googled the issue and went all pale, and/or
c) CDP group has a lot of chinese investors (more than 60% are publicly traded) who were not amused, and/or
d) They are genuinely afraid to lose something on the Chinese market - which is huge, but I don't how much of a foothold GOG had there. There are a few active Chinese users here on the forum, and there could be a ton of customer who might be pissed off by the game.
Seeing how 10c is the biggest entertainment company there, and western companies need approval from 10c (or other CCP approved companies with party representatives), I'd say it might be because CD Project Group wanted CyberPunk 2077 (especially), and past and future games to be sold there.