Why would that be fraud? Is the subsidy something other than giving the people purchasing EVs a "rebate"?

A good lawyer could argue that Tesla must be aware that exiting the auto market would immediately crash the value of all existing Teslas because it would essentially create a sunset date for those vehicles, given how much software they're running. Good luck to anyone trying to sell a used Tesla once that announcement is made, because who would buy a car that is going to be bricked at some point?