Why would it come up, they were not grandfathered in, they were eligible because the Constitution made special exceptions for those that were here at the adoption of the Constitution.
People at the time were not idiots, they could actually read.
In the real world what we think doesn't matter in the least, they will do what they want to do, and we will find some useless prattle to post on a web page, and eat our peas.
If Conservatives can revise the Constitution when it suits their needs, then it doesn't matter what I think, because the Republic is dead and the Democracy that the Founders tried very hard to prevent, will be established forever, or at least until enough patriots rise up and reject the Zombies.
What you don't seem to get is that it is the birthers who are attempting to revise the Constitution to suit their ideas of what it should say.
And there is not the slightest doubt about this. Not one significant authority in the entirety of United States history, conservative, liberal or otherwise, has EVER interpreted the Constitution the way that birthers do. Not one single significant legal or historical authority has EVER given "natural born citizen" the meaning they give it. Not one single bona-fine published textbook in American history has EVER said that it takes birth on US soil plus citizen parents to be a natural born citizen.
There's no real legal or historical argument here at all. Not among the people who deal professionally with either history or law.
The ONLY people making this claim are a bunch of people on the internet who have little understanding of either history or law, but insist that they do.