User A messages user B using iMessages. User B screenshots all of those messages and uploads them unencrypted to a random FTP server. Now replace the random F

User A messages user B using iMessages. User B screenshots all of those messages and uploads them unencrypted to a random FTP server. Now replace the random FTP server with iCloud. Or Google Drive. Does that change the nature of the messaging between User A and User B? I would say it doesn't. In fact, WhatsApp does basically the same.