You are correct that the courts have not ruled definitively on such a person's eligibility.
My point is, whether the courts have ruled on it or not, from the point of view of history, the related law that we do know, and the intention of the Founders, such a person is eligible. And if Cruz runs and a case reaches the Supreme Court, they will rule that he is eligible.
It is in my mind a mere formality that the courts haven't (yet) ruled that a Ted Cruz is eligible.
I also believe the courts would rule in favor of Cruz’s eligibility. I just wanted you to acknowledge what we both know 7 FAM 1131.6-2 states on the subject. Thank you for doing so.