This is possibly the easiest online discussion type or "template" to implement. It is indispensable in any new or redesigned online course. I call it "see the forest discussion," but most people call similar activities "exit tickets." The interesting part is that it isn't really a "discussion" in the strict sense, but is worth considering, if you don't use it.
This is a really simple “template” for a week-long, time-sequenced online “jigsaw-type discussion,” and its potential effectiveness in promoting recall, and transfer of knowledge, is based on fairly basic, but solid, and well-established research evidence summarized at the end of this post.
Online discussions in some ways they are better than traditional face-to-face synchronous discussions. They are more equitable, giving everyone time to think, and leveling the playing field for intro- and extroverts (who are always guaranteed to win in face-to-face discussions!).