OP, I'm going to give my speculation in answer to your question. I know that you were not trying to bring up racism - just asking about habits and patterns.
It's only my experience and many of you might disagree, but twenty or thirty years ago there was a perception that gay Asian men in NYC were clingy and pushy. There were far fewer Asian men in town and many were living in fairly closed communities. Homosexuality was so shameful in most Asian cultures that it seemed like the only gay Asian men you encountered were men who could never pass as straight. Stereotypes about being small of frame and penis were reinforced by my experiences. Communication could be difficult as the language barrier was still quite strong.
Now NYC has a large population of Asian students and graduates thanks to NYU and other educational institutions. Due to improved nutrition, Asians are rapidly gaining size in all areas. And of course the internet made communications much easier. It's no longer unusual to meet a straight appearing, tall, well-hung Asian and for better or worse, those are qualities a lot of gay men find attractive.. However, assumptions take time to fade and I think the idea of Asians as "other" is still around for some.
As for racism and fetishization - these are just words that people use to judge and control the behavior of others.
People should associate with, and have consensual sex with whomever they want. for whatever reason they want. Excluding any group means missing out on a lot, but that's a choice.