I don't understand your comment -- are you implying the holocaust didn't happen or wasn't genocide? I want to steelman your argument but it's pretty hard.

Your other point is that you wonder whether a paper review is going to protect against mass killing. I'd say yes, that's quite possible. Anyone can post almost anything they want on any kind of blog or 4chan sub or reddit sub, and that's fine. But scientific papers are what people quote as "truth", and publishers have some responsibility in making sure that what they publish is based in evidence. This is especially true when it concerns topics that have, historically, led to genocide.