To sum up: If the platform becomes the "information content provider", defined as "any person or entity that is responsible, in whole or in part, for the creation or development of information", then they loose the protection. The statute also excepts federal criminal liability and intellectual property claims.

Creation or development of information can exclusively be moderation, as has been shown in copyright cases. Cutting (deciding what to show and what not to show), re-arrange or changing the context can create new original work, which would make the creator an information content provider for that. At the same time, doing either of those does not automatically cause the moderator to become a creator of original work.

As lawyers like to say, it all depends on the details of the specific case. To take a extreme example outside of this twitter discussion, taking an video interview and cutting it to create a new narrative would make the editor responsible for that whole new version.