It seems Meta recently migrated all Messenger chats to e2ee. But if you had created a secret conversation (e2ee) in the past then instead of migrating the existing chat Meta decided to archive and switch to the secret chat.
Since I only experimented with/created secret chats in the past with close friends and family, all my old conversations with years of history were archived with no path to restore.
This is a horrible UX experience and absolutely ridiculous that this design passed in Meta.
They have none of the benefits of ancient, dinosaur email.
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