I don't think history is how white people have presented it, but I'm pretty sure no government has the resources to fabricate an event of that scale.
That said, to be 100% blunt, I think people who weren't present at the Holocaust and are more than 1 generation removed from the horror, need to get the fukk over it. Japan committed fukkloads of war crimes in Asia that were literally just as bad or even worse than the shyt the Nazis did to the Jews (look up Unit 731:
Unit 731 - Wikipedia, the free encyclopedia), and 70 years after they dropped the bomb, most people no longer give a fukk. My great-grandfather was killed by the Japanese, but even though the older people in my family don't necessarily trust them, we're like whatever. We had Japanese products in the house growing up. Go to any Asian country, talk to Asian Americans, you'll find lots of young people that love anime and manga and all that shyt.
I'm not trying to be insensitive, but if people weren't there and their parents / grandparents were not personally traumatized by that shyt, they need to get the fukk over it, and stop using it as an excuse to play the victim 24/7, or justify doing horrible shyt like the actions mentioned in the OP.