There is no way VW will fix the cars and sell them to new owners without the complete emissions system installed. New owners of the fixed cars will not have a reason to be upset.
VW might not be happy about needing to add missing parts, but I wonder how many of those parts will be reused anyway.
On top of that, if the fix was going to be that good, that they would be able to make money buying the car back, adding and replacing whatever parts are included in the fix, refurbishing the car, and THEN selling it for profit, I doubt we would have the option to sell the car back.
I don't know if there is any way VW can sell the cars in another country (some people have said the court papers forbid it), but maybe there is some kind of value in that form.