"used as" is not the same as "is". However, this is further muddled by government involvement into businesses, making them quasi-government. Argument could (in my opinion, easily) be made that public companies are, well, public, and would fall under restrictions of the First Amendment. Interestingly, Twitter is now Private, so they wouldn't be subject.
This is a still not all 230 is about, with the Publisher/Platform aspect, but I think would make for interesting court cases on their own.
230 going down entirely would be devastating, but also really, really, really funny.
I don't think the automation tools would work, either in practice or in being upheld as being "enough" in the court of law. I think what would happen is every large-scale site - Twitter, Facebook, YouTube, Twitch, etc. - would simply be unfeasible, and thus cease to exist. Everything would have to be treated as a Publisher, like a Newspaper or TV Channel - invite-only, curated, approved. Social Media would just... die.
Lots of ramifications to that, and I can easily see the good in it, along with the bad. Regardless, would be very interesting.