That report only says that Reddit banned some subreddits and so mitigated some speech, on reddit.com.
But Reddit is not the entire internet, and that ban perhaps directly fed into 8chan's rise. People do not disappear because a forum went offline, and tools to communicate are only getting better, faster and more resilient.
When users have to migrate, plenty don't bother to. Not every extremist visits sites specifically for extremist content. Many people pick up extremist ideas just because they're popular where they were already browsing, and the reverse can be true. https://www.vice.com/en_us/article/bjbp9d/do-social-media-ba... and https://www.nytimes.com/2018/09/04/technology/alex-jones-inf... have examples of various media personalities (Milo, Alex Jones) that became much less popular once they were de-platformed from their main point of presence. Their fans and popularity could have followed them ... but mostly didn't.
Isn't that again just focusing on singular points instead of the whole picture? Who is popular now that Milo and Alex are less so? Has that been measured?
It seems highly dubious that all that attention completely disappeared instead of following other channels, which may be even more extreme. I can't find any study of this.
There's 0 negativity in this post and literally describes how a majority of 8chan's Pol board got a wave of user's same when people were getting banned on 4chan's /pol/ they just got routed to a different site.
These individuals dont disappear and it really doesnt take long to route to a new site. Fixing the udnerlying problem is a better idea than covering it with a band aid
But Reddit is not the entire internet, and that ban perhaps directly fed into 8chan's rise. People do not disappear because a forum went offline, and tools to communicate are only getting better, faster and more resilient.