Some very solid thinking in this post. I would add that the reason for the time limits has more to do with the accumulation of storage costs as well as attempting to prevent abuse by having the whole community focused on "today" and not an ever growing body of content.
Some random thoughts, allowing someone to mint a NFT for a piece of content may be a way to recognize long-term value. For example, someone could buy the paper on general relativity and it would be a massive collectors item. 99% of all content needs to be forgotten as only 1% is truly evergreen.
Your concerns are legitimate, but the solutions are not so obvious when you factor in the tendency of people to game the system and you attempt to avoid token-weighted voting.