Congress cannot change the definition of a word in the Constitution. Natural born for the purposes of being eligible to be President will forever mean whatever the Founders believed it to mean at the time of the adoption of the Constitution.
There are two ways to look at this. The theory, and the practice.
In fact, we are under a lawless and corrupt government, that has subverted the constitution in myriad ways. A new Declaration of Independence would read just like the one with the July 4, 1776 date on it.