I don't know whether to blame the professor or the students here--my gut feel is to blame the professor.
I taught at a far less "prestigious" university and that wasn't my experience. I used to record all my CS lectures and practically all my students showed up anyway. And I never took attendance.
Even when I had a "marketing and sales" guy come in to deliver a lecture for me (because, let's be fair--a significant fraction of CS students are going to wind up in non-tech roles so students need exposure to that side, too), practically the whole class showed up. It completely stunned the poor presenter flat who expected that maybe one or two students would show up and instead wound up with a full house.
If good students regularly aren't showing up for lectures, the person delivering the lecture needs to do some serious soul searching and fix the content of the lecture.
If I am not doing that, what's the point of a "lecture"?
Otherwise, you might as well read a book. It's faster than a lecture, likely more thorough, and not tied to a specific timeslice.
I was one of those students who didn't learn by actively participating and I always felt like I had trouble learning in class. The school I did my PhD in started using online tools for some of the courses and I found that I learned way better when I watched the online lectures. A big issue I always had in class is when the lecturer explains something that is obvious to me in great detail, or just speaks slowly in general I find myself daydreaming and once I snap out of it I may have fallen behind and not be able to follow the rest of the lecture well. Online lectures at 2x speed are way more interesting for me and I almost never daydream. If I feel tired I can pause for a couple of minutes and stand up and stretch or walk around the room. If I miss a detail I can go back and replay it again. I would still attend office hours and email the professors though. What I learned from the online lectures also stuck with me much longer.
At the end of the day, students are paying an enourmous amount of money to learn, and I feel it shouldn't matter if the way they learn it by not showing up to class. Especially if they learn it better by not showing up to class.
Okay, that's a LOT of missing context.
Having a "discussion" section is unusual for most universities outside of beginner prerequisite classes. And, office hours have never been mandatory for students anywhere I have taught.
Given that, yeah, I can see that interrupting a lecturer is problematic and that watching a recording is probably okay.
Probably not the case and they just structure their own course to be similar to MIT's courses.