Google has an IPv6 measurement page that reports that their numbers report on the percentage of users that access Google over IPv6.
According to the report by Jan 2020 0.3% of users in China used IPv6 to access Google
However, looking at this metric in dynamic we see the substantial drop starting from June 2019.
I failed to find any solid news that may cause such behavior. I have two hypotheses in mind.
- Also as it is a percentage metric, they can adjust their calculation on the total internet penetration rate in China.
- Previously open discussions between netizens took place on Google Plus groups. In April 2019, Google shut down Google Plus. Technical discussions continue on Chinese-language blogs, forums, and groups. For obvious reasons, discussions must be hosted outside China, and posters must register under pseudonyms. So probably that caused the shift from Google services but I hardly believe that it may cause such plummet.