For Cruz to be a NBC he would need to have been born in the United States to two parents who were each a citizen of the United States at the time of his birth. This would make him a citizen without necessity of statute--or--a "natural" citizen
Cruz is an American citizen by statute. And what the statute bestows, the statute can remove. This is why the Founders insisted that the POTUS be a natural citizen of the United States.
I stand corrected.