you could save some storage with this, but i don't think it's a good idea. a lot of people expect the threadiverse to have a lot more permanence than e.g. mastodon, similar to reddit. being able to find old posts/comments about a certain topic is one of the things that made reddit as useful as it used to be, especially when searching for tech related issues in my experience. old doesn't necessarily mean obsolete, and whether this would be suitable would be highly dependent on the community. most communities are not intended to be for ephemeral content only.