Is anyone surprised that reddit is threatening to remove mods and replace them with others? This has happened before, there's actually a lot of precedent for when a subreddit is abandoned and things like that. You could always "apply" to own the subreddit and it was generally not too much hassle if the previous mod ignored it.
What will be interesting is seeing just how many mods actually step up to fill those shoes. Will they be power-hungry, ineffectual mods or will they be just competent enough to keep the lights on? Will reddit eventually have to pay some mods, or do they have enough goodwill to keep these new mods happy?
Reddit actually has a huge problem with some mods being responsible for like 80% of the major subs on the site. There was a lot of conspiracy talk around that, but regardless of the merit of such conspiracies, it'll be interesting to see what happens to those users - do they care more about staying in power, or do they care more about the platform they manage?