It’s not a stretch. For starters, they’re not editing the speech of others. Refusing to publish is not editing.
"Refusing to publish" is editing content by ANY measure.
Define "editing content" in a way that excludes REMOVING content. I'll wait.
Deciding not to publish is a first amendment issue. You can’t claim damages for a decision not to publish when you have no right to it.
Deciding not to publish WHAT? Why?
Florida has a cause of action for REMOVING content in an unfair or non-transparent manner. It specially points to "bad-faith" actions in those decisions.
While social media can still remove the content or "refuse to publish" content, they will still pay the price. Government cannot restrain speech, but if you slander another, you will pay damages for that free speech.