The film in question: https://www.youtube.com/watch?v=bvLT8U0-_lI
It baffles me that the creators would bother with this little disclaimer, as if to say "we're not racist" before espousing claims that rival Nazi beliefs. What motivated this preface? Why would they bother to try and promote this kind of plurality of America while being so virulently racist in the same breath?
The point of the disclaimer was not to say "we're not racist," but more "don't be racist to the good Nisei boys in the 442nd RCT. They're American."
It didn't much work, but at least they tried.