Pretty much all non-Japanese food in Japan is some form of “cultural appropriation” to the extent that it plays into stereotypes/tropes Japanese people expect from that given “cuisine”. For example, Italian would consist of lots of cheese. Japanese “Italian” food is in a category of its own. In this case, it would be actual appropriation because it’s made by Japanese people rather than the given ethnic minority putting a spin on their cuisine. Best comment I’ve ever read on Reddit is that the Japanese don’t like cheese, they like the concept of cheese. Japanese people can’t stand strong smells nor spice, so that already greatly restricts the authenticity of food.

The exception would be if the restaurant is catering specifically or exclusively to the immigrant population. I’ve found this to be common in Vietnamese restaurants where it’s just a community hangout spot for the migrant workers.

Since you live in Yokohama, the entire town plays on stereotypes and tropes of what Japanese think of Chinese. Namely, all the fortune teller shops since the Japanese think Chinese people are mystical (the Western version is fortune telling machines feature an automata wearing a Turban or Gypsies).