According to the message of WABetaInfo, the developers of WhatsApp released a beta version 184.108.40.206 of its messenger for Android, which contains a new function of sending multimedia messages with expiring date.
This feature, like the expired messages feature, will allow users to send multimedia files (images, videos and GIFs) that automatically disappear when the recipient leaves the chat room.
WhatsApp will allow users to send such multimedia by pressing a new timer button. When clicked, the button will turn green, notifying that the multimedia message they are about to share will automatically expire.
However, unlike expired messages, media files used with this new feature will not have a specific expiration date. They will disappear as soon as the recipient leaves the chat room. There will be no traces or deletion messages left in the chat.
This feature is currently in the testing phase, but WhatsApp may add this feature already in the next stable build. So far WhatsApp does not publish official information about this feature.