WhatsApp is set to introduce a new feature which will give users option to accept or reject group invites. According to WhatsApp BetaInfo, the feature is in three levels, everyone (the current setting), which allows everyone add the user to a group, My Contacts, which only allows those in the user's contact list, and Nobody which when enabled automatically blocks group invites.
To enable the feature, the user would have to go to the WhatsApp Settings - Account - Privacy - Groups.
In the event a group admin is automatically blocked, an invite would be sent to the user in form of a new chat. The invite will only last for 72 hours before it expires.
After invite expiration, the user will have to receive another invite or use the group's invite link to join the group.
Though the release date was not disclosed, the feature will be made available to iPhone users first on the next beta updates.