Tesla is taking a slight cost risk that ultimately all customers will want to buy the Supercharger upgrade and receive unlimited, free long distance travel for life.
By making the power of the national government essentially unlimited, the logic required to sustain the ACA would squeeze the life from the constitutional framework of federalism, a cornerstone of the Constitution.
This is a bedrock argument of the Obamacare foes, and it must tiptoe around some inconvenient facts of daily life such as state car insurance mandates (they are state laws, and states have practically unlimited powers under the Constitution).