Cultural appropriation is confusing to me to begin with, I’ve said it on other Q’s. I grew up with my grandparents and aunt traveling and bringing home jewelry and clothing from other places and we loved the different styles and fabrics and wore them appreciating the other cultures.
As far as food, fusion is an accepted culinary style and also is a natural evolution of food preparation as people migrate around the world and travel. Most “ethnic” food in America has been Americanized to fit the taste buds of Americans. For instance, my Mexican husband would never put cheese on a pork (carnitas) taco, but I’m guessing plenty of Americans would. I hear people from the UK make fun of how Americans put cheese on everything.
Sometimes populations that move to new regions or countries can’t find the same ingredients and they improvise, and so that changes the dish over time.
Vietnamese and French is a common fusion.
My aunt used to love to go to a Chinese Cuban restaurant as a child and order pork fried rice and plantains.
Some flavors just don’t go together. Nori and mac and cheese, a hard no from me.
People can put together whatever they want.