Had a quick look at desuarchive.org, and it seems like people are slowly coming back, but there does seem to be a sizeable contingent who has decided to stay at 8moe or one of the many boards past or present that took in refugees during the hack. Maybe they just liked the idea of a board more tailored to their community, and they can head back to halfchan whenever they want. If nothing else, this was possibly the equivalent of moot's gamergate banning spree for 8moe.