Do you mean that Congress can change by legislation the definition of “natural born citizen” to mean anything that it wants, just to suit the needs of the current situation? If that is so, we the people no longer have the final authority in determining the terms of the social contract under which we have been operating for the last 233 years.
The meaning of the Constitution should mean only what the framers intended that it mean.
For example, what if Mom and Dad (Natural born US citizens from Rio Linda, California) are on vacation in Berlin and baby comes a month early? Eligible to be president?
What if Dad and Mom are NB citizens, Mom is in Army, in Iraq, pregnant and baby is born there? On US base? Off US base in Iraqi? In back of jeep by US military doc? Civilian US doc. Iraqi doc? Hungarian Marine Corps medic?
What about same couple are on US Delta flight from NY to LA? What if it was a Air France flight? What about on flight from PAR to ROM? What if flight is on Alitalia (Italian flagged) from Rome to Milan, over Italy? What about if on Continental over Taiwan on flight from Hong Kong to Tokyo?
(All are considered Natural Born)