This feature does not require an active internet connection on the primary phone.
A specialized site has leaked valuable information for WhatsApp users: the multi-device function, which is soon to arrive.
This new function promises the user to use the same account on different devices at the same time and without the need for the application to be active on the phone, so that it could be disconnected, for example. However, the company is developing two different avenues to have it open, thanks to the beta update 188.8.131.52 for iOS.
Multi-device with WhatsApp Web: you can use WhatsApp Web without your main phone to be connected to the internet.
Multi-device with other devices: you can connect up to four different devices to your main WhatsApp account – however, this limit may change in the future – and you don’t need an active internet connection on the main phone either.
This novelty is useful for those who use two telephones: one personal and the other for work purposes, for example. In addition, the feature does not require an active internet connection on the main phone.
How to send messages to yourself on WhatsApp and what it can do for you
WABetaInfo has published a video in which it demonstrates how to log out of a WhatsApp account from a linked device, and shows a new option called “Log out” that allows you to unlink your device to the main WhatsApp account.