Do you see the words “Natural Born Citizen” anywhere in that section of the code? It’s not there. Even if it was, the Congress cannot, by the simple passage of a law, change the meaning of Constitutional terms.
We all are. The People. The States. The Federal Congress. The Federal Executive. The Courts. The Juries. All.
I believe that would be the federal courts,since they have jurisdiction over all cases and controversies arising under the Constitution. Now each branch can make their own interpretation when passed laws or governing, but in the end it the Court that decide if others do not agree with their interpretation.
But one Federal District Court case does not precedence make.