Also, you know, you're working with kids. Slavery is a fact of history but it's a painful one for kids to understand and there are better ways of doing it.
It's like how you don't lead 7 year-olds into the Holocaust Museum and say, "who here is Jewish? You would have been gassed with your Mommy!" There are better and more sensitive ways of approaching the truth in a way whose first message isn't to restate the dehumanization.
Your comment would make sense if anyone was being "dehumanized", but the original article does NOT support your wild conclusion.