The comments on this are wild. Like, I remember the scene they're talking about. As a fully formed adult knowing and seen and experienced the horrors of our world and system, this scene did stick with me. Yeah you can watch a documentary and read all the papers and watch true crime or whatever. But I think it is fundamentally correct for a child to interact with these really difficult topics through a scene that directly happens to the MC and his friends that hammers home how dehumanization works and why it works. This isn't a scene that comes up in passing, it's a process that the MC and his friends, who you are actively rooting for, goes through. And to hear it happen to a real life person, probably for the first time, would be shocking.
It's why story re-enactments of history works so well. It gives personhood to the events that helps people understand WHY what happened was so bad by giving you a face to empathize with directly. It's why reenactments have existed for, forever and why oral stories teaching kids important life lessons featuring concepts they were already familiar with was so important.