Auto-deleting messages and decentralization are an incorrect fit. Don’t enforce memory policy centrally. The edges know their context best.

To me, decentralization means two parties work out how to trust each other directly, sans intermediary. Unless read access to self-destructing data is controlled and limited by a trusted 3rd party, access can’t be revoked. Choosing that 3rd party usually means centralization.

Not auto-deleting messages also makes positioning against legacy social clearer. They keep your messages indefinitely and one bad breach away from leaking. We keep messages too, but in a distributed way so there’s no central store to breach. It should be easier to not fear enduring messages in a distributed system.

It’s like the DRM problem. Unless the data is only touch by signed centrally trusted software all the way until the hdmi cable, you can’t keep the video safe. But the problem is worse with messages since using a client that backs up all messages while pretending to delete is trivial to build.