Yes, it's the ability to use your WhatsApp account from 4 devices at the same time.Under development, but it's great!
— WABetaInfo (@WABetaInfo) June 12, 2020
Testing 👀When someone adds a new device in his WhatsApp account, you will be notified because encryption keys change.Available in future for iOS and Android! pic.twitter.com/WqrM6cRHWW
— WABetaInfo (@WABetaInfo) March 24, 2020