I wonder if not everyone is reading the article? I think it’s 100% fine for a prof to assign seats, I don’t even think it’s that weird. The problem comes in the details.
1)When kid showed up to class someone else was sitting in his assigned seat - so professor has no problem with kids sitting in incorrect seats.
2) the person sitting in his seat left at some point and professor continued class.
3) 5 minutes later professor asked him to move.
Those are all strange. If the professor cared why didn’t he tell the person sitting in the incorrect seat in the beginning to move??