Weakening the liability shield will result in the companies blocking *more* posts
How do you figure that?
In the days of printed newspapers, the publisher chose what to include. That didn't work online, because comments are posted on their site until and unless some person or mechanism takes action to remove or prevent it.
This is flipping the posture from "default deny" to "default allow". So instead of holding a (print newspaper) publisher accountable for what they choose to print, the potential now was to hold a site liable for what they choose to remove.
Section 230 was designed to protect sites for removing offensive content, so they could crack down on people spamming sites with - among other things - porn, which happened a lot in the early days of online comments.
Removing the protections of Section 230 would make open comments untenable for providers, meaning they would be forced to adopt the default-deny posture of print publishers.
It takes childish short-sightedness to think that repealing 230 is a "win", and that providers won't do anything in response.