"PruneYard Shopping Ctr. v. Robins, 447 U.S. 74, 88 (1980) (upholding a California law protecting the right to pamphleteer in privately owned shopping centers)"
I think of the platform like a shopping center, once you open it up to the public to enter they can say whatever they want to anybody else in there and nobody can determine the subject or viewpoint they are allowed to hold or communicate.
Once a platform opens up to user content I see it as the same thing, just because the reach is bigger and it is digital should not make any difference, when we are all retired our kids will send us to sleep in a capsule plugged into the metaverse and wired up to a nutrient supply drip like the matrix - do you want to be censored in there ?
anyway that's my 2 cents. I am sure people smarter than me will see a lot wrong with this and happy to hear about it.