The airplane technology that Tesla's Autopilot is named after is also an assistive technology, not a replacement for pilots. The complaint people have around the name is that people don't understand what autopilot is, not that Tesla are equivocating.
Much effort is expended on branding and naming. This would, at a bare minimim, include a basic consideration of how a word is commonly perceived, irrespective of whether the common perception is accurate.
Tesla is fully aware of the cachet that the name confers upon the brand, while displaying it prominently and relegating the absolution and disclaimers to the finer print. I like Tesla. I admire Musk's acumen and vision. But, here, they are certainly equivocating and it's irresponsible.
Language evolves. If the vast majority of people understand by Autopilot the capability of driving alone without assistance, and you know it, I don't care that the proper textbook definition of that technology refers to assisted driving.
I agree that relying on archaic definitions would be sneaky, but I'm not talking about "the proper textbook definition," I'm talking about how it's used in the real world by people who actually create and use autopilot systems in airplanes. Just because some people use "quantum" to mean "huge" (e.g. "It's a quantum leap forward") doesn't mean somebody is being disingenuous to use it in the sense of "a minimal amount."