I don't think the issue is so much with the name "Autopilot". The issue is more to do with the name "Full Self-Driving". That name definitely suggests the car is driving itself.
Furthermore, back in 2017-2018, Tesla had a section on the order page when you would add FSD that described the car being able to do short and long trips with no action required from the driver. See below. That description certainly seemed to give the impression that the car would be able to drive itself:
Of course, there is also that disclaimer that states that functionality is dependent on validation and regulatory approval. So, one section says the car will drive you from A to B with no action on your part and the other section says "we can't promise when this will happen".
There is also this page before you order a Model S or X that claimed AP2 cars have the necessary hardware for full self-driving at safety greater than human: