2020.48.35 supposedly introduced the improvements with a caveat that "Before this feature can be enabled, the latest version of Navigation maps must be downloaded via WiFi.".
That was immediately followed by no update until now.
Release notes and statistics for 2020.48.35 with Navigation Improvements, Autosteer Stop Sign and Stop Light Warning, Dynamic Brake Lights, Text Messaging Improvements, Unlatching Charge Cable, QQ Music Improvements, TRAX v0.2, Sentry Mode Improvements and more.
teslascope.com
(I have to select "Show more" on the left to see the navigation bit on Teslascope for some reason, even though it's for all models)
My car has downloaded the update sometime in the last few days, I noticed it this morning, but I haven't been anywhere to see if anything has changed - although as no-one has said anything here I don't expect that it has.