The Log out option, for now, replaces the Delete my account option in Account settings, but this may change according to the report. WABetaInfo also shared a video of the feature in use and it shows that tapping the Log out option takes the user to the “Agree & Continue” start page. The report adds that this feature in beta works in both WhatsApp Messenger and WhatsApp Business. While the video is on an iOS device, the report also states that this feature will be available on Android as well.
The implementation of this Log out feature suggests that WhatsApp is working towards releasing multi-device support as the ability to log out of a device would be important if logged in to multiple devices. The report points out that multi-device support is being implemented in two forms, one for WhatsApp Web and the other for different linked devices. The first will allow users to use WhatsApp Web without the main phone needing an internet connection. The second will allows users to link their WhatsApp account with up to four different devices. This also does not require an active internet connection on the main phone. WABetaInfo also states that this limit of four devices might change in the future.