you can read messages that have already been deleted from your Notification Log on Android phones. While it isn’t a big flaw, it’s still a strange discovery.
The Notification Log application, as the name suggests, is a dashboard for all notifications that come to your phone. While a “deleted message” has actually been removed from WhatsApp chat thread, the message (in the form of a notification) is still available in the Notification History.
the app does not show only the preview but the entire message. Notification Log records notifications locally. The app allows you to browse and export the recorded notifications (JSON format).