It is autopilot (a poor one but still one) that legally calls itself cruise control so Tesla wouldn't have to take responsibility when it inevitably breaks the law.
Real Autopilot also needs constant attention, the term comes from aviation and it's not fully autonomous. It maintains heading, altitude, and can do minor course correction.
It's the "full self driving" wording they use that needs shit on.
Newer "real" autopilot systems absolutely do not need constant attention. Many of them can do full landing sequences now. The definition would match what people commonly use it for, not what it was "originally". Most people believe autopilot to be that it pilots itself automatically. There is 0 intuition about what a pilot actually does in the cockpit for most normal people. And technology bares out that thought process as autopilot in it's modern form can actually do 99% of flying, where take-off and landing isn't exempted anymore.
Looked it up some, In ideal conditions, and with supervision. The pilot can't just take a nap and forget about it. Which, two Tesla's credit when you activate the feature for the first time it does make you read a large unskippable warning that you need to be paying attention at all times. I still don't mind the name autopilot I just hate that they are marketing it as fully autonomous self-driving because that's the part that implies you don't need to be watching over it (to me)