Think this case in particular is pretty interesting. Former default subreddit and one of the largest on the site (Top 20 at least).
I think /r/videos is where we’ll see how things actually play out with the reddit admins. I’m guessing at some point the admins will step in and replace the mods.
Twitter just needs warm bodies. Reddit relies on users to run the communities. That’s the difference. Reddit is the only big site right now where a small number of users leaving angrily can cause serious structural issues for them.