I was familiar with this teacher's work, but had never seen the full video. I was struck by her use of 'red, white, black, yellow' to designate skin tone and cringed a little bit, since these are very out of usage now. However, I applaud her work. It doesn't surprise me that it took a short time for the children to 'turn.' I am familiar with both the Stanford Prison Experiment and The Wave, and how quickly those involved turned. She was definitely playing with a bit of fire there, but she did it extremely artfully. For 19 years I taught in a very diverse school, children from all over the world, and yes, racism/prejudice came up from time to time. I tried to meet it head on, and use it as a teaching moment.
During my years teaching, I encountered a lot of unfamiliar names that I had to learn to pronounce. Since my last name is so frequently mispronounced, I have always been sensitive to that, so I made an effort. I asked students to correct me if I pronounced their names incorrectly. I assumed that is what you did, what all teachers did. I was disappointed to learn I was wrong; some of my colleagues often complained that they couldn't pronounce certain names, and wished the students would take "an American name." I found that abhorrent.
Ms Elliot was ahead of her time in conducting her in-class experiment. But no teacher in 2020 could ever do something similar and keep their job. I watched part of the full documentary with the 'grown-up' children, and not sure how much their 3rd grade lesson truly impacted their adult lives in their small, segregated town. Baby steps.
You're right, a teacher couldn't do that today. The blowback from parents would be extreme, depending on the community of course. Couldn't get away with it in my middle-class upwardly mobile district where I taught (I'm retired now). I also wondered how much of the lesson they retained. I remember teaching about drugs and alcohol to third, fourth, and fifth graders. Of course they all said "drugs are bad, I won't take them." But I know for a fact that later on, some of them did, and some of them got into serious trouble making poor choices like that. I think the same possibility exists with the antiracist message they received at this young age, unfortunately. There are so many other influences outside of this single classroom.