Of course, if you are still delayed because of some inevitable things, there is still a live playback video to watch. But I'm more used to watching live broadcasts than watching replays myself. You can discuss with each other, study together and have any questions you don't understand in class anytime and anywhere in the comment area of the live broadcast room.
You can also ask the teacher at any time, and the teacher will give a very professional answer. Other friends can also make progress and study together. Of course, if you watch the replay class by yourself, you can always ask the teacher if you have any questions. It will be easier to cooperate with your own learning progress, which is still good.