[Ajedi32]

Disappearing messages were never a real thing in the first place. You can have a gentleman's agreement that the person you send your message to will delete it after reading it, there's no way to guarantee anything beyond that.

(Fair point though that probably "disappearing" messages shouldn't be included in backups since that obviously prevents them from being deleted. Idk if Signal implements that or not.)

[tptacek]

Disappearing messages are an opsec feature for trusted counterparties, not a cryptographic feature. They are very much a real thing.