Growing up in the Mid Atlantic (VA)I'd agree with you, but having spent 6 years in Southern New England during the early 70's I have heard the term used as Trump used it. I would conclude that it's a local usage. However, Trump IS from that area, so I would give him a pass, with the warning that he should only use it with local New York audiences.
Naw. He just educated the entire country. Bringing us together !