I don’t know if I’d call them ethnocentrist either. The Meiji era was about reforming Japan to adopt many western standards, and even today, you see non-US influences like kpop waltz right through cultural barriers, despite any presumed ethnic prejudice.

I would argue they try to hold more rigid definitions, so to be “Japanese”, etc. is a stricter standard than what Americans will see as “American”. From how they take and refine ideas that are new to them, I think their ability to evaluate foreign concepts is actually quite open.