They were trying to make the point that these insular platforms are something conservative Republicans are cooking up on their own, but the behavior of the other major social networks attempting to insulate their platforms first and foremost is what is creating these conditions across the board for everyone.
Action, reaction.
Private platforms, newsgroups, bbses, and forums are nothing new for the internet, I wouldn't even know if I would call these apps social networks in the sense of a wide reach like Twitter and Facebook have, but it shouldn't be surprising that if you deplatform a group of people and/or make their political views against the terms of service, that they'll go somewhere else, and if the other place they go to happens to be an echo chamber of political thought built from the ashes of actions committed by other social networks with a perceived political bent, it shouldn't be surprising that the political activism gets ramped way up as a result.
In my opinion, and this goes for both groups, not exposing yourself daily to conflicting opinions and different solutions to problems is intellectually damaging, and I firmly believe how most major social media companies are handling discourse in our country is extremely short sighted and damaging for real problem solving and conversations going forward. The first amendment and free expression is supposed to be an ugly, gnashing, frothy thing full of intellectual guts and blood. Bad ideas and bullshit solutions should get their guts ripped out in spirited debate, and we aren't doing that anymore.
From my perspective, Reddit, Facebook, Twitter, et al are close minded companies ran by intellectually weak and close minded people with a myopic world view and it's going to fracture things further, not help it.