Thankfully, as the AP piece points out, these cases are unlikely to fly.
Section 230 still stands, and I'm pretty sure Facebook/Google/Twitter are acting in good faith when they ban someone for promoting known false election claims that lead to sedition and violence at the US Capitol. Thats on top of past violations on Trump's part. He was given every exception and still pushed past the limits.
There's also the basic matter of the First Amendment. Private companies are allowed to choose what goes on their own platforms, so long as they aren't violating other laws in the process; they weren't violating laws by giving Trump the boot.
I wouldn't be surprised if these cases are dismissed before they even reach trial. And oh, how I'd laugh if they are.