So the argument that it's a purely private platform is getting harder to make than just the Facebook use-case where "all my friends use it", which you could also say about iPhones, or Coca-Cola. Should a private company be allowed to ban you from what's becoming a de-facto platform for interacting with officials?
But the article lazily likes to pretend that this problem could be solved within the borders of the US with proposed FCC regulation. That still leaves the most interesting problem, which is how are we going to square the free and open Internet with the interests of nation states and their individual citizens.
There's complaints about Russian election interference. But right now US-sponsored election interference is happening in Venezuela via Twitter. What's to be done about cases like those? Is Venezuela's only recourse going to be to ban Twitter?