WABetaInfo has reported today that the WhatsApp beta for Android 184.108.40.206 update has introduced the ability to approve new participants for group admins. At the moment there is only a toggle to enable or disable this feature, and there is no existing area for approval requests to be found as this feature is still under development.
As previously reported, Meta has been announcing a range of privacy upgrades that are coming to WhatsApp over the coming months. These include things such as more granular settings for online presence, blocking screenshots and leaving groups silently, so this new feature further adds to the list of improvements.
It doesn't say where the feature will first begin rolling out, and whether this option is available to all users of this version of the beta. With the initial update 2.22.18.09 rolling out yesterday, then an update to the feature that informs members of the group as a banner message has rolled out today.
This feature will be a great help to groups who have many members and admins, particularly those that are more public facing with join links available online. Overall, it shows that Meta is putting a lot of work into improving WhatsApp in recent months.