Yeah, and all of that's already true right now because messages are stored on those users' devices already. You'll be heartbroken to hear that those users can also take a screenshot of your disappearing messages and send it to anyone. There are fundamental limitations to what a messaging app can protect you from.
While the analog hole will always exist, and you can't make it actually impossible, Snapchat's quite good at that screenshot thing. Both platforms have APIs to prevent, or at least notify on the use of screenshot. It's weird that signal doesn't use any of them.
i know of ~3 currently working methods to take screenshots on snapchat
it isn't "weird that signal doesn't use any of them" because it does [1] use both, just not for giving a false sense of security to your correspondents
