TL;DR – Now, this is NOT a hoax.
While we had reported just yesterday that WhatsApp will not be notifying you anytime soon when someone takes a screenshot of your chat, there have been news today of a new feature that will allow users to revoke sent messages that have not been read.
This means that you can delete messages sent via WhatsApp before they have been read by the receiver.
The new function was first discovered by Twitter account @WABetaInfo. If you take a look at the screenshots above, the deleted message is replaced with the notification, “Sender revoked the message”.
So while the receiver will know that you had indeed deleted something, it would still possibly save us from a lot of embarrassing situations.