As a German, this entire things feels always so bizarre to me. If a teacher “over here” would try and make their students do something similar for the German flag, said teacher would get kicked out of the faculty pretty quickly.
The same goes for religion by the way. While we did have classes about religion for a while (Katholischer / Evangelischer Religionsunterricht), the teachers were more or less just explaining what certain passages of the Bible meant, how they had been misinterpreted in the past, what is similar or different between certain religions etc. but not even they were allowed to make their students actually pray.
PS: and those were optional classes by the way. If your parents didn’t want you to attend, you didn’t attend. No discussion.