I just read the article. The ostensible reason for this is that they were worried about privacy for the other students in the class. In other words, you are watching the zoom class and you are seeing the other students faces and part of their room or home in the background.
Maybe they are worried about some deranged person developing an unhealthy fixation on some student. But of course, that can happen anywhere.
Then disable the video feed so that only the teacher can see the students and the students can only see the teacher. Weak argument.