While our phones are encrypted and prevents people from unlocking it unless we authorize them, that doesn’t mean that all our contents are 100% secure. This is why despite it sometimes being a bit redundant and inefficient, having extra layers of security might not be a bad idea, especially if you deal with sensitive information.
The good news for WhatsApp users is that it looks like WhatsApp has finally rolled out a self-destructing messages feature called Disappearing Messages. When enabled, messages will automatically be deleted after 7 days, although this only affects messages sent after the feature has been enabled, so your past messages should still be safe if you want to preserve your chat history.
That being said, WhatsApp does acknowledge that there are certain limitations to this. For starters, all users need to have the feature enabled for it to work. So if person A has it turned on but person B does not, then it won’t work. Also, WhatsApp warns that there might be instances where disappearing messages aren’t deleted, such as when they’re shown in unattended previews in notifications, if they’re quoted, or forwarded to another chat where Disappearing Messages are not enabled.
However, the feature is there if you wish to take advantage of it, so make sure you have the latest version of the app.