Range assurance on a non-tech car? Well yes, the release notes say we have it. But distances to chargers without turn-by-turn navigation are as the crow flies. The car has no idea of your route to the Chargers. Until Elon converts our non-techs into aero cars, IMHO range assurance on non-techs is no assurance.
This has been discussed already. All of the cars will work this way. It will probably account for this by some margin of error. Meaning, as example, let's say as the crow flies you are now 50-miles from the nearest charger, and your car has only 70-miles of range, it might warn you then with a 20 mile buffer. Or it might be percentage based--- when "as the crow flies" you are now far enough away that you'd arrive with less than X-percent, then it warns you. And chances are good X-percent is something stupid-high like 20.
See my thread the other day about trip planner. It waned me to stop and charge my car at 22%, rather than drive home and arrive at home with 17% (there is a supercharger about 5% SOC range away from my house, en route). Strange stuff for sure, but Tesla wants to make sure you charge, and i'm certain they will have, even using crow-flying distances, play it safe. Their reputation is on the line!