Earlier quoted context omitted.
I think the GP post was specifically saying that if you're a "platform" you cannot moderate content. You are required to distribute anything users write on your "platform" that is not illegal (in the US?).
The platform operator can't. That's how common carriers work (telephone, your ISP etc.). But things running on that platform could. Basically look at reddit and perhaps take it up a notch. If the platform operator does not want to be associated with some of the stuff happening on their site then perhaps they should deemphasize their branding. It wouldn't be "reddit/watchpeopledie" just "watchpeopledie". I not sure ho…
And that’s different from present situation because…? We already have Twitter Prime (Twitter), as well as the constellation Twitters — Conservative Twitter (Parler), Nazi Twitter (Gab), [Niche Interest] Twitter (various Mastodon people instances), etc. We haven’t fundamentally changed anything; all we’ve done is move the moderation “problem” around a bit.