I think that article is full of baloney, Joe.

People of the N.E. United States often have a legitimate eastern accent. There's the Boston accent, the New Yawk accent, the Bronx accent, the sound of downeast Maine.

I believe it also occurs in Michigan and parts of New Orleans.

Think of your tongue. It has the tip, where we say T; it has the back, where we say hard G. In between is the center, the part we hardly think about. Now start talking English aloud and hold the center of your tongue flat and still. You will start talking with a NE accent.

It's called 'centering.'