Regardless of the jurisdiction at birth, if they aren't under US jurisdiction they aren't subject to US laws.
Jurisdiction is largely a matter of geography. If you move, the jurisdiction changes. It doesn't matter where you were born, it matters where you are (or where you were when the act in question occurred.)
There would have been no such clause in the Fourteenth amendment if jurisdiction has no real meaning. Foreigners legal and illegal are still subject to the laws.