This feature was discovered by WABetaInfo, the online platform tracking WhatsApp’s upcoming changes and features. It is not yet available to the public, but it may be launched soon.
According to the website, when this feature is enabled, users will be able to send disappearing messages with new chats.
This is because the platform already has support for enabling message disappearing with a chat, but only after the chat has already started. This can be done via Contact / Group Info> Disappearing Messages.
Upcoming support for Disappearance mode is added below App Settings> Privacy.
Currently, the Message Disappearing feature provides support for messages to disappear after 7 days. However, it has been reported that WhatsApp is working to offer 24 hour support as a disappearing message window.
This was discovered last month by WABetaInfo who claimed that this feature will be rolled out on iOS. Android and web / desktop through a future update.
A message’s 24-hour lifespan is expected to be added to the “Messages Disappearing” section, which currently gives you the “On” or “Off” options, which set the default message disappearance to 7 days becomes.