No, there are tons of regular office computers and even home computers that run XP. Industrial computers in China would actually be running fairly up to date OS's compared to, say, US.
I visited a number of factories in China last year and saw lots of XP on measurement, production and test equipment. All the office desktops were on W7 or W10. I'm sure lots of XP desktops exist, but I didn't see any in the (quite many) offices I passed through. I can't speak about home computers, I only saw a small handful.