It's not a matter of whether a naturalized citizen can become president. The question comes down to whether there are two classes of citizen (natural born and naturalized) or three (natural born, citizen at birth but not "natural born" and naturalized). Since there are two and only two jobs where that distinction matters, the president and vice president, I'm not surprised that it has never been clarified by law.
It HAS been clarified. The WKA decision is clear, which is why every case that has gone to judgment cited it and decided that anyone born in the USA is a NBC.
I think the only question that has never been clarified by the courts is if a person born abroad to two citizen parents is a NBC. State courts have said yes, but the Supreme Court hasn’t faced a case like that.
“The question comes down to whether there are two classes of citizen...”
There are no “classes” of citizenship in the US. All citizens share in the same rights and responsibilities.
There are however different qualities of citizenship.
The US Constitution, in setting out the eligibility requirements for holding National elective office, has required that the office seeker posses certain qualities of citizenship, the main one being the NBC requirement for POTUS.