I am not a NY person. Yet I do this. One of my parents is from Buffalo though. I had no idea others did it! I thought I had a weird 'rude' quirk that I had to stomp down. I had to distinctly learn how to wait for the pause and how to interject at the 'just the right moment'. Instead of just getting it over with and blurting it out. I know there are all sorts of accents and customs. But today I learned about this one. Cadence is important too. I took several of those online 'where are you from' verbal tests over the years. Those can be kind of fun, I usually get 3 very different places. One somewhere I have never been and the other 2 are where I grew up and where I currently live. I talked a few dudes in another country to take the test. It thought they were from the New England area.