But in terms of the appropriateness of calling the feature “autopilot,” it seems that Tesla’s feature is as deserving of the name as an airplane’s autopilot (the driver/pilot still has to remain alert and focused on what’s happening).
autopilot is the lane guidance of the skies that maintains basic stability not a level 5 system. people hear autopilot and think it means it does "everything."
further muddying the waters, tesla maintains their car has all the hardware, sensors and computation to support fully autonomous driving. it's just that pesky software missing.
FWIW that's not necessarily true either, autopilots run the entire gamut from "maintains trajectory and altitude" to "automated flight from takeoff to landing" (only the taxiing is left to the pilot).