Reports further suggest that the QR code scanning feature of WhatsApp may also allude to the multi-device account support that is expected soon, which may also be coming soon. Since WhatsApp is tied to phone numbers, adding a contact number is enough to add a contact to your WhatsApp contact list. This opens up a new page within the app: on the first tab, you can view your own QR code, and on the second tab, you can scan QR codes from others.
Additionally, if you happen to share the QR code with the wrong person, you can reset it and generate a new one, without limitations on how many times you can do this. Under their personal QR code, they will find a "Scan" button.
When you share a QR Code with someone, you are sharing your phone number, too. All this is identical to the new experience for beta testers on Android. If you an iPhone user, you can head into the app's settings to see a new "QR code" icon next to the username. You should, therefore, install the beta update only on your secondary device and just to see the changes.
On Android Beta for WhatsApp, users can access your WhatsApp QR code from the Profile section in the Settings menu.
WhatsApp Now Lets You Add People Using QR Codes; Currently Limited to iOS Beta
Elsewhere, there's also clues about the new Password Protect Backups feature.
The feature is available today for users running the 2.20.171 beta version of WhatsApp on Android. The objective of the feature, as its name suggests, is to protect backups that the instant messaging app creates with a password.
The feature has been in development for more than a year, and will offer full encryption for your conversations, including conversations stored on iCloud. Users would be asked to use a case-sensitive password that they need to provide whenever they require the existing backups - mostly when reinstalling the app.
These new features making to Beta app version usually means that the it might make it to stable version, if tested successfully.