[[Is that child “natural born”? The courts would probably say yes. But I say no.]]
Did the child renounce his us citizenship? No- the only way to lose NBC is to renounce your citizenship and declare allegiance to another country - that child is always a US citizen until they themselves decide they no longer wish to be-
Ah, but that leads to a very interesting question. Can a person be a natural born citizen to two countries at the same time? Can you be both a NBC of Canada and a NBC of the US?
I say no. But I suspect I'd be overruled by folks in black robes who went to law school while I was working in a steel mill.