This would be a good use case for private posts on self-hosted Movim + XMPP. Only your followers can see the posts but they persist unlike messages which tend to fade either due to expiry or just being too far back in the history. The XMPP platform’s clients come with OMEMO for double ratchet E2EE & Movim has a slick progressive web app for anyone that doesn’t want ta install some app while being able to comment on posts, participate in DMs+audio/voice calls, as well as MUCs (multi-user chat).