Nothing changes in normal chat usage
In fact, nothing changes in normal messenger usage. WhatsApp has been sharing data on Facebook since 2016. Many may not be aware of this, but TECHBOOK did among others This was reported in detail. In the EU, data transfer is more severe than anywhere else. For EU residents, everything will be the same.
Follow the steps: WhatsApp will access this data from your mobile phone
On the page, WhatsApp explicitly states that interacting with companies is completely optional. Users have control over whether they want to contact companies via WhatsApp. You can block contacts at any time and remove them from your list. Chats with companies are also explicitly marked so as not to be confused with casual chats.
WhatsApp also tries to ensure that chats between users are still encrypted from end to end. So the content of the messages cannot be accessed to WhatsApp or Facebook.