The long-awaited charging adapter - CCS Combo 1 (CCS1) to Tesla proprietary standard - was launched first in South Korea in October. It's compatible with the Model 3 and Model Y only and can provide over 100 kW of power, according to tests.
The company has promised that the adapter will be available in North America "soon", but sales have not started yet, while the imported adapters were initially not working in the U.S.
2021.40.6 software update
Things changed in late November with the 2021.40.6 software update, which displays info about the CCS adapter support. In the Controls / Software / Additional Vehicle Information menu, one can find CCS adapter support is "Enabled" or "Not installed."
Here, you can see an example report from a Tesla user who notes "Enabled" support in a 2022 Tesla Model Y Performance (December 2021), and lack of support in a 2019 Tesla Model 3 SR+.
According to various reports, it appears that cars produced before 2020 (and some in 2020) do not have the hardware to support the CCS's communication - most likely they don't have the Power Line Communication (PLC) chip, shown here.
As we understand, only the newer Model 3/Model Y will be compatible with the CCS1 to Tesla adapter, while other cars will not (at least, not without a hardware update).
It's an open question whether the refreshed Model S/Model X will be compatible with the adapter in North America. A report on Tesla Motors Club forum indicates that the refreshed Tesla Model S also displays support for the CCS adapter.
Anyway, lucky owners who see CCS adapter support is "Enabled" should be able to use the CCS1 to Tesla adapter once it is available (or even imported units).
A successful test with an imported adapter
Drive Tesla reported on November 30 that one of the Tesla Model Y users, who got the CCS1 to Tesla adapter in South Korea, was able to successfully use it after downloading the 2021.40.6 software update.
The car was tested at a 350 kW Petro-Canada charger in Vancouver, British Columbia, Canada. According to the report, charging power peaked at 110 kW, "before tapering to between 77kW and 90kW for most of the charging session." The state-of-charge (SOC) increased from 36% to 42% within 2 minutes.
It's great news for many Tesla drivers, which soon might be able to purchase the adapter (once it finally arrives) and expand their fast charging capabilities.