It got popular during ww2 yes, but it was still in Italy, even if it was served to American troops. And dismissing any previous history of the dish as "ahistorical" is really weird.

I think the transformation into big-C Carbonara is what’s being described rather than any of the many styles of carbonara that existed in many forms depending on who and where you were in Italy. What became popular was palatable to Americans. So if it’s dismissing something it’s dismissing that carbonara is any single thing throughout a heterogenous country and that it somehow defines italianess.