One in thirty-seven Americans live in NYC. Anyone who follows finance or media (those little things) is looking towards NYC a few times a day. New York is a massive, globally trend-setting market. The entire business model of haute couture is basically to be successful in NYC with insanely expensive (and sometimes ridiculous) outfits that only a handful of people wear, and let the buzz drive slightly more rational sales elsewhere. Hell, just think of the cronut. The lines forming to get those things were making international news before one went uneaten long enough to leave Manhattan. You can pick at the chip on your shoulder all you want, but it's laughable to say that a product that is only popular in NYC is a flop.
Throw in the part where the OP said, "if you go to a place like NYC..." and was quickly followed up with confirmation from Tokyo, it would seem the original point never was about "only" seeing a product in one city, but actually pointing out that a luxury item doing well in mega-cities is not just a relative success, but maybe the exact intention of a company notorious for targeting the high-end market.