I find that hard to believe. The last few times I've been to China (in 2019), none of the hotels I stayed in (all of them in Shanghai) had ipv6 for their guest WiFi.

I think it's a problem with the legacy infrastructure of WiFi hotspots in the hotels instead. And the final steps of the deployment were in October 2019, I think. Most mobile applications, China Mobile and China Telecom, both landline and mobile connections - everything works with IPv6 now. Even big corporate networks started to do the switch.