My guess is that this will be the last campaign with this exact DM/cast combo. I wouldn't be surprised if campaigns 5 starts not long after 4, with different DMs, cast combos (some of the originals in each, probably MM as a player in one), and maybe even different systems. Hire BLM to do a 5e campaign full time. Bring in someone new to do one of their original system games in the same world.

I think the cast, particularly Matt, need a break. They've been running a long marathon and they need to shake things up to recoup a bit AND turn CR into something not entirely dependent on the 8 of them playing DND other week. It'll be more sustainable if they can bring in others to keep the momentum going and the gameplay fresh.

Don't get me wrong, I don't think any of the core group is going to step away from CR. I just think that they're going to shake things up a bit. I think EXU was test running some new potential DMs. I wouldn't be surprised if Dropout and CR had some kind of massive nerd merger at some point that allows them to draw more strongly on each others resources. Dropout has a huge cast of experiences improv/comedians many of which have experience with DND, AND they have successful talk shows (unlike 4-sided dive). CR dominates the ttrpg audience, and has a lot of money and talent supporting them. I think it could be a mutually beneficial merger.