Can’t speak to evolution, but you’ll hear the old school accent (real, not the “boids” cartoon version) anywhere that doesn’t get a lot of transplants. Bay ridge, Bensonhurst, corona, Astoria, midwood, Staten Island, etc.

In some cases as other socioeconomic and ethnic groups have moved into New York they have picked up features of traditional New York speech.

The most prominent example I can think of is Cardi B. She has a heavy Bronx accent, and will say “talk” and “walk” in the old New York manner of “tawlk” and “wawlk”.