WhatsApp is introducing a few changes affecting media sent in connection with self-deleting messages. This affects both the latest beta versions and the stable versions of the app for iOS and Android.
The visibility of media files is now automatically restricted, i.e. images, videos and audio files that have been supplied via the self-deleting messages. For example, they cannot be accessed via the gallery of the respective end device.
The change affects both Android and iOS. Under the Apple operating system, the content no longer ends up in the camera roll. However, you can still bypass the whole thing by manually saving the files you want.