Nice assumption but wrong. In reality, in the 12 seat cabin there were two "non Japanese" Passengers (us ) and 10 passengers looking very Japanese. Guess what ratio of meals were loaded - not 6 / 6, but 10 / 2. I assume only 12 meals were loaded ( unless they had many spare western meals ). Racial stereotyping driving catering at its best. It may be only a short regional 73H flight", but 4 hrs nevertheless
I don't believe there was any trumping by the other pax - it was just the crew ignoring my specific request.
Even if it's 10 / 2, still only take 10 JMB elites to trump you. I wouldn't say it's impossible for the Tokyo-Taipei route.
Personally I had always got the meal I requested since I become a JMB elite. Not a Japanese but no problem of getting the Japanese meals at all on long, medium, and short haul flights.