An integral part of Fiat's ability to buy a larger percentage of Chrysler, was predicated upon Chrysler building a small car and building a car that achieved 40 mpg.
That happened at the beginning, its in the agreement. Its easily researched. The 500 was that car.
Now it has been supplanted by the Dart.
That obligation has been met, the 500 is VIN'd as a Chrysler for that precise purpose, that purpose has been fulfilled, now 500 can go back home and be imported to the US for the few who wish to buy one.