@scottjenson Not critical, as I wouldn’t expect it because of the current implementation.
If a future iteration of PMs would change that implicit feeling, it might as well be a good idea to communicate it explicitly in the UI, e.g. at the beginning of a new conversation. Basically the opposite of what WhatsApp does (see screenshot).
Also, if encryption means it’ll harder for third party apps, services,… to adopt PMs, then I feel like it’s definitely not worth the effort.