I absolutely can say that because you don’t know the definition. All you know at this point is that he will have to be a US citizen. You have no idea how the court would rule or what law would be passed by Congress.
You can have legal discussions all you want about what the founding fathers INTENDED...but at this point...there is no definitive definition...so yes, it is POSSIBLE that he could be an NBC if born in Kenya and she wasn’t married since that would bestow US citizenship.
That bestowed citizenship would have been via statue. Are you, therefore, arguing that someone can "obtain" Natural Born Citizenship via statue?
Requirement: Born on US soil???