Not for some online courses.
Some courses have group meetings online.
This varies by course. For some courses you leave your written comments or work for others to see, and check in at a later time to pick up the responses to those messages. But you might also have a group meeting of a few students to discuss the work that was posted. Some courses might have very little interaction online between the students. These meetings are scheduled as part of the course but have the same flexibility that is a key part of online courses.