Re: If you are contracted….
When you enter into a contract (such as when you buy a car), all parties make certain representations. For example, the buyer promises to pay the seller a certain amount and the seller promises that the car has particular performance and features etc.
In this case, the customers paid extra for the promise that they would receive certain additional features by a specified date*. Tesla appears to believe that it's operating in the wild west of software, where features are added and removed at a whim, might not even be fit for purpose and promises of delivery dates are ethereal. I doesn't work that way with motor vehicles.
* While perhaps not common for motor vehicles, this is not an unusual clause to see in a contract. Once when I bought a property, the seller promised to have certain structural certification work completed by a particular date after the contract settlement. There was a financial penalty associated with them failing to do so.