A friend of mine did an assembly the other day where he argued that the "Holocaust Memorial Day is counterproductive, as by institutionalising the day we either (a) brush it under the carpet or ( Have a tendency to focus on the Nazi Holocaust of Jews and label it as a "German" crime. In other words, it breeds prejudice and bigotry in a minority, and apathy and complacency in the majority - exactly the sort of thing which helps to create the conditions for another one."
It sounds like a stimulating assembly. I am not sure I fully agree with it but he was clearly right to question this process. He definitely gave the students (and staff) something to think about.
Many years ago I started a PhD (I later turned it into a MPhil) into the role that school plays in the development of political consciousness. This include a study of school assemblies and the way they impacted on the students. My research showed that the vast majority of students did not listen to the assembly. (Although they liked them as they saw it as a gentle introduction into the school day.) The main message they got from these was that morality was about obeying those in authority.
However, I discovered that some assemblies did make them think deeply about issues. In most cases this involved assemblies given by someone who rarely gave them. If they used a different approach, especially if it included drama, they did take note. I have always thought that schools underestimate the ability of students to think deeply about moral issues. However, before you can do that, you have got to let them know that you really are interested in what they have to say in the issue. Lectures are totally ineffective in this process.