Having lived in Japan for 2 year and working in what one would hope being a very educated environment (Todai and Rikadai PhD candidates), I can personally account that the number of Japanese who actually know about that bit of their history is few. Culturally, they don't speak about this topic - and there if something is not spoken about then it does not exist. I would not be surprised if some teachers could simply not cover that bit of the programme without any consequences; Japan is specifically good at not following its own laws, when such laws have been written mostly to appease international observers - same with women equality and discrimination of minorities laws.