I wonder about those different platforms. They already exist — Gab simply isn’t that popular. Revoking Section 230 would expose Gab to a “Thiel vs Gawker” situation: a billionaire could sue them into extinction. That doesn’t seem desirable at all.
If FB's status changed, Gab could theoretically become more popular. Not all new platform/publishers would be the equivalent of a Gawker and thus raise the ire of a billionaire. There are plenty of independent journals, magazines, blogging platforms, etc that don't get sued out of existence.
Please don’t make accusations of astroturfing. It’s rude and against the HN guidelines. Why? Because the majority of the time, it’s not true. I don’t work at or have any connection to Microsoft, but a week ago, I was accused of astroturfing for them because I did not agree that them open sourcing stuff is EEE.