Nothing changes in normal chat usage
In fact, absolutely nothing changes with the use of your regular messaging program. WhatsApp has been sharing data with Facebook since 2016. Many may not have known this, but TECHBOOK among others has. I mentioned extensively about this. In the European Union, data transmission is more stringent than anywhere else. For residents of the European Union, everything remains the same.
After WhatsApp has already made these changes As a status message imposed on its users, A banner should now appear above your chats. If you click on it, a page appears To which the changes are explained.
On the side, WhatsApp explicitly states that communication with companies is completely optional. Users control whether they want to contact companies via WhatsApp. You can block and delete contacts from your list at any time. Chats with companies are also explicitly tagged as such, so as not to be confused with regular chats.
WhatsApp is also trying to confirm that chats between users are still end-to-end encrypted. So neither WhatsApp nor Facebook will be able to access the message content.