The new look is found in version 2.23.8.4 of the Android WhatsApp Beta app. To find out which version of WhatsApp you are using, open the app and tap the three-dot overflow menu icon on the right top of the screen. Go to Settings > Help > App info. Wouldn't you know it, the version of WhatsApp Beta on my Pixel 6 Pro is running version 2.23.8.3. Oh so close! Eventually, the feature will also be found on the public version of the app although it might take a few weeks before this happens.
With the navigation tabs on the bottom, the Android version of WhatsApp will match the iOS version of the messaging app. The WhatsApp iOS app already has the navigation tabs at the bottom of the screen. Moving the tabs to the bottom of the screen is something that Android WhatsApp users have been asking for and now WhatsApp is giving them what they want.

The Android version of the WhatsApp Beta app will have the navigation tabs moved to the bottom. Image credit WABetaInfo
With WhatsApp, users can enjoy messaging that is protected with end-to-end encryption, make phone calls, and engage in video chats. The Meta-owned platform has over 5 billion installs on Android alone and counts 2.24 billion global active users. 100 billion messages are exchanged over WhatsApp every single day. You can install the app on your Android device via the Google Play Store by tapping on this link. Apple iPhone users can install WhatsApp from the App Store by tapping on this link.ncG1vNJzZmivp6x7sbTOp5yaqpWjrm%2BvzqZmp52nqHyiusOrpqKcXay1osDSmqepZZKawaJ51KmbmqyVYrqwwsSsZKeZpp60osDIqKVmrJGXwKC1w2prb29kaw%3D%3D