I think that works. Since the playoff games are one after another and don’t happen at the same time, the daily game thread won’t be cluttered.
I don’t think there will be a lot of discussion on the play-in, so one thread for the entire tournament should work. Maybe just post a reminder the next day that points to the original thread, so it shows up on people’s feeds. I admit I haven’t been able to participate as much on game threads because I simply just forget as it doesn’t show up on my feed.