Ahhh, so Macaroni was Frencified form of dandyism and the use of Macaroni "style" by colonists was a yokel attempt to be fashionable
Now in the article the author says :
The entire Yankee Doodle lyric, one of America's most beloved patriotic songs, is a joke at the expense of the Colonists.
So it seems to me that the Yankee Doddle Song, written to ridicule the American colonists was adopted by them and made their own.
Nice trick! Make it your own and take the sting out of it.