The window sticker isn't a binding agreement
There is (to my knowledge) nothing legally binding about the Monroney.
Now wait a minute. While I agree in principal that one is not entitled to that which one did not pay for me.... the Monroney sticker is something else entirely.
It is not merely a convention. It is a legally-binding requirement, as codified in the US code, title 15 sec 28
[USC02] 15 USC Ch. 28: DISCLOSURE OF AUTOMOBILE INFORMATION
Every manufacturer of new automobiles distributed in commerce shall... securely affix to the windshield...a label on which such manufacturer shall endorse clearly, distinctly and legibly true and correct entries disclosing the following information concerning such automobile—
..the retail delivered price suggested by the manufacturer for each accessory or item of optional equipment, *physically attached to such automobile at the time of its delivery...
So while the bill of sale did not match the sticker, that is the dealership's responsibility, and does not obviate the need for the correctness of the sticker...the retail delivered price suggested by the manufacturer for each accessory or item of optional equipment, *physically attached to such automobile at the time of its delivery...
From a legal point of view, the selling entity (=Tesla) is liable to be penalized up to $1000 for this.
From a practical point of view, Tesla should either offer customer that feature at a discount (say, the equivalent of their $1000 fine); or, at this junction and under these circumstances, given that it occurs no additional cost*, just provide that software for free.
*the pedant will hang on the word 'physically', but this law being 60 years old (though later amended) didnt take into account software, but any reasonable person will argue the software counts as optional equipment in the spirit of this law.
**i work in software, i know the software has value, even if it incurs no incremental cost to deploy. but in this example its simply a matter of good customer practice.