Don't be obtuse. (Unless you really can't help it.) The act being discussed applied to children.
Yet for years Congress extended citizenship to those whom another country could claim as citizens:
Yeah, so? "Citizen" does not mean the same thing as "Natural Born Citizen." Congress doesn't have the power to extend or give "Natural Born Citizen" status.
for example, the mothers of presidents like Wilson and Hoover. I don't know the precise details, but dual loyalties and dual citizenship were probably involved there as well.
Why do you not know that is completely irrelevant? Prior to 1934 the wife of an American was immediately naturalized upon marriage. Children born to the marriage were Automatically "Natural Born Citizens" if their father was an American.
But Britain (or Canada) would still have recognized the mothers as subjects. So far as I know Wilson's (and Hoover's) mother never officially renounced British nationality.
Hence the children would have dual citizenship. With regard to their mothers' British (or Canadian) subjecthood, they would have been born with a (theoretical) dual loyalty or allegiance. Hence, by some of the natural born citizen theories, Wilson (and Hoover) would have been ineligible for the presidency.
Why do you not know that that is completely relevant?