Until model year 2020, the model year changed over with the calendar year. Around ~10/20/2019, 2020 VINs started appearing. On 10/5/2020, 2021 VINs started appearing.
This seemed to indicate that Tesla had made the shift to introducing the next model year in Q4 of the current year, like most other car companies, rather than on January 1st, like they had done up to 2020 model year.
I had hoped that 22' VINs would appear early in October/Q4 but I still expect them to happen at some point this month, if it is following the most recent trend.