Non serialized 80% receivers are still available and being legally sold, so, I’m not sure about this article.
Possession of kit guns has been made a felony in many states, including mine. The case is to determine the unconstitutionality of such laws.
As soon as someone figures out how to un-invent something, we can start talking about making something illegal to possess.
My favorite Clarence Thomas quote: “Sometimes bad policy can be Constitutional, sometimes good policy can be unconstitutional. That’s why we go to the text.”
In some instances, you can make the case that unserialized firearms are bad. But, there’s a stronger case under the 1st, 2nd and 4th Amendments. 5th too.