It should be noted that up to 15% of all hibakushas were Koreans, who were seen as second-class citizens in Japan in spite of the government propaganda that annexed Koreans are given same rights as Japaneses. So the lack of statements about wrongdoings of the former Japan empire, including WW2, is certainly relevant here.
(Just in case, Nixon Hidangyo is clearly aware of this and has campaigned for proper recognition of Korean survivors for a long time.)