WhatsApp is developing a new feature called "Delete Messages", which will allow users to set their messages to self-destruct after a specified period of time.
Messages that have been deleted automatically have been around for a long time Telegram and can be enabled in private conversations on both iOS and Android.
Η application WhatsApp will activate the automatic deletion messages in all conversations and this feature is already available in the 2.19.348 beta for Android devices. It's called Delete Messages, and it can be activated from the Contact Information screen, but also available in groups if administrators enable it.
Auto-delete messages on WhatsApp will come with several preset values namely 1 hour, 1 day, 1 week, 1 month and 1 year. Support for preset message deletion time doesn't seem to be fully defined yet, but these features are absent from applications of the Telegram.
The new feature is already at an advanced stage, as it even supports the dark mode of the application. The dark mode for WhatsApp is yet to be released publicly, so there is a chance that both new features will be released together.