According to Sawyer Merritt's unofficial report, Tesla will phase in the updates to all Model 3/Y that are produced in California and China by Q2 2022.
The list of updated features includes:
- AMD Ryzen processor (accelerates the entire infotainment/navigation)
- lithium-ion auxiliary battery (replaces 12 V lead-acid auxiliary battery)
- heated wiper park (at the lower section of the windshield)
- 13 speakers (down from 14) plus subwoofer ("no appreciable difference in sound quality")
The switch to the lithium-ion auxiliary battery - which has a slightly higher voltage (15.5 V, 6.9 Ah) according to reports - will require a new power conversion adapter to enable the Trailer Auxiliary in Model Y. The new adapter (retrofit) is expected to be available in mid-2022.
"Trailer Auxiliary (tow hitch enabled vehicles): It's been disabled. New 12 LV Li-ion battery requires a new power conversion adapter to be compatible with 12-volt trailer power. Adapter will be available in Mid-2022 & owners can retrofit then. Trailer lights/brakes not impacted."
No other retrofits are planned, which means no AMD Ryzen processor for the older Model 3/Model Y to accelerate their infotainment/navigation.
"Finally, Tesla notes that they have NO plans to offer any of these options above as service retrofits. That includes the AMD processor."
There are actually more changes that Tesla applies to the new Model 3/Model Y (some - reportedly leaked - were listed here). The one thing that is sure is that Tesla continues to update its vehicles pretty often, not waiting for a model-year changeover or new generation like the automotive industry usually does.
Update (January 23, 2022): New unofficial reports confirm the lists the 2022 Model 3/Model Y changes in Europe: