Growing up this topic was one of two I had a teacher that you could just tell wanted to break down in front of the class and just cry while they went over the course of the material for it. You could just tell he was so sick to his stomach about covering it but it was important to cover so he pressed on.
I had some teachers who would skip over things they were supposed to cover but did not because it made them feel unconfirmable talking about it. I’m glad unlike some of my friends who had a teacher who shorted the amount of time the class spent on it. That my teacher did not.
I doubt they ever talk about Van Chhuon or lest I don’t recall. I just recall some of the photos and a video that was shown. Some things you never forget and for good reason. We can do better as humanity than those times.