tbf there is not really a good solution to the ‘ephemeral aspect’ problem

the only way to truly not sync metadata to or btwn servers at all is to use a p2p model, in which you cant send anything if one of the parties is offline

simplex might be a bit better in this regard, but still relies on servers for syncing. at least it doesnt extensively replicate metadata like matrix does though

so it depends on your threat model whether this is a compromise or not