If this is how Cruz obtains citizenship then he is not Article II eligible.
Do you agree?
No, of course I don't agree.
Multiple early sources equated citizenship at birth with natural born citizenship, or said that the President had to be a citizen at or by birth.
Most contemporary scholars believe that people born US citizens abroad are eligible. I do too.
I believe Ted Cruz is eligible. It's not 100%, since the Supreme Court has never specifically ruled. But I think that almost certainly he's eligible, and almost certainly the Supreme Court would agree that he's eligible.
I understand your opinion, however according to the law you cited Sec. 301(a) he is not Article II eligible. Thank you for agreeing.