The issue is whether children born to parents who have ILLEGALLY entered the US AUTOMATICALLY become US CITIZENS.
The Wong case did NOT involve this situation because both parents were here LEGALLY.
The 14th Amendment was intended to effectively repeal the original Constitution's 3/5 calculation for congressional representation and other references to slavery. In order to do so, it used exactly the same terminology ("persons") as the original text. This was also used to clarify the citizenship status of the children born to former slaves, not to confer citizenship on the children of people who were temporarily/illegally visiting the US.
P.S. The term "persons" was used in the Constitution's original text because there was no such thing as "citizens" prior to its adoption.