> 3. Not. We've experimented with this internally but so far have not decided to release ephemeral aspect to public. Not enough demand. As someone else commented - you can delete content from your devices (syned across if you're logged in from more than one), but content will remain on other people's devices.
You may not see demand, but the userbase for an app like Wire or Signal is itself very small and with almost no demand (compared to just having a messaging app with emojis, GIFs and stickers, for which there is a huge demand - encrypted or not). :)
I use this feature in Telegram called secret chat with the self-destruct timer set to a specific duration to exchange sensitive information like banking information or other things that I don't want to remain for long.
(By trusting Telegram's encryption for secret chats) This makes it quite simple to exchange information which otherwise would involve asking people to delete specific messages or wondering if someone really deleted it or just forgot to do it because of laziness, forgetfulness or just being busy (not attributing malice to the other party here, since the information can be captured for posterity through many other means).
I hope you would consider this feature even if you see "not enough demand", because for those who need it, it's a real blessing to have it!