Apparently they're giving up on finding a mainstream host and are going "dark web" accessible only by Tor...which is basically just an invitation to post stuff that'll get some people a visit from the FBI.
FWIW I've heard that it's basically been leaked by some within Reddit that the only reason some of its most vile subreddits are still up (such as probably the worst of the worst: r/Physical_Removal) is because the FBI has asked Reddit not to take them down and is asking for info on various posters on them.
That's probably a good thing given that it limits their audience to just the freaks on the dark web and keeps them from influencing impressionable angry young men.
I'm sure the FBI will still be able to monitor them on the dark web.