The idea is good. The only concern is the fact that there is no more the "live" part.
The attendees could be less engaged: such recordings could become like any other youtube video. The thought that there is a "real" instructor, that the class is "live", looks more compelling that looking at a recorded video. Same thing for the instructor: recording a session, talking to nobody, is less engaging compared to the idea that there is a "live" audience looking at him while he is speaking.
On the other hand, a recorded session has many advantages and it's worth exploring this path. At the end of the day there are many issues with the live sessions, as well described in the wiki page. One of the many advantages is a better organization: the instructor can record the session when he/she has time, we can edit the video, we don't have to be in a hurry. Also the discussion forum is a great idea.
I like this idea as well. I would be very interested in being an instructor for this. I think that it would be useful to have a monthly/bi-monthly live Q&A sessions, strictly for answering questions. This might add more of the feeling of a direct connection to the instructor that students get from a live instructor-led session.
I see one major downside of the "connecting the instructor to students" bit. It is a ONE -MANY relationship. That is, one instructor is connected to many attendees. By moving the Q&A to a discussion forum, the relationship becomes MANY-MANY, i.e., many community members (including the instructor) can connect with many attendees (and attendees can connect with other attendees too). I prefer the second since it connects the whole community to attendees instead of one community member---and it would likely increase the chances of attendees turning into contributors too (which is a sub goal of these classroom sessions).
If we must, be can have live Q&A sessions, but they could be done like an AMA (ask me anything) instead of over video chat? I see no reason why it must be limited to video chat. So, what if we put the recordings up, and then we ask the instructor for a Q&A session? For example, this can even be over IRC in a meeting in #fedora-classroom, and we can bridge the channel to Telegram to make it more accessible also. Even the live Q&A sessions still suffer from all the same issues though: timezone, limited time, scheduling and the effort that needs to go into all of this from the team's perspective.
I think that while live Q&A sessions are a "nice to have", the forum for post-session discussion is necessary.