WhatsApp notified its user about new privacy policies which needed to be accepted before 8 February for continuing the account on WhatsApp or they can delete their accounts. New policies include data sharing with Facebook. This spurred many people- including Elon Musk to call for users to switch to other more privacy-focused messaging services like Signal and Telegram.
Facebook informs those same data-sharing policies will not be applicable in "European regions"- which covers EU, EEA and post-Brexit UK but have to accept the new privacy policies. Though, new version policies for European users mentioned that data can be shared with other Facebook companies. This is because of the recent changes in the EU privacy regulators.
In a FAQ post, WhatsApp replied that it shares a wide range of data such as phone numbers, payment details, status, IP address, phone model, etc. with other Facebook companies. Facebook has not replied about sudden changes.