Yeah that is a great point and something that I think could be accomplished quite easily. In fact the idea of try social accounts that would be UI specific would allow this, but then that content would only be seen on that UI. I’m not sure of a technical way it could be picked up by each front end but not be held on chain, but maybe there is a way.
I think giving users ownership and choices with their data is pretty powerful.
RE: "Why in the world would I want my tweets immutable?" - A Case for Censorship Resistant Social Media