I was looking for a reply in a post earlier this year but then found it's gone. This is kinda a downside, I wish old replies could be re-fetched, never thought it's "impossible to undo".
It could work in a way it would backfill the replies once the post is accessed, but tech-wise I understand if it's not possible.
Question for admins: Are you doing something to circumvent this?
Masto.host suggests this should be left blank. Never realized how dangerous this is for the content on your own server.
https://masto.host/mastodon-content-retention-settings/
#MastoAdmin