"Does this apply to the UK and the EU though?"
From WhatsApp's European Economic Area FAQ (which claims to include the UK still, updated Jan 4, 2021):
"WhatsApp also works, and shares information with the other Facebook Companies who act on our behalf to help us operate, provide, improve, understand, customise, support, and market our Services.
"This includes the provision of infrastructure, technology, and systems, e.g. for providing you with fast and reliable messaging and calls around the world; improving infrastructure and delivery systems; understanding how our Services are used; helping us provide a way for you to connect with businesses; and securing systems.
"When we receive services from the Facebook Companies, the information we share with them is used on WhatsApp’s behalf and in accordance with our instructions. Any information WhatsApp shares on this basis cannot be used for the Facebook Companies’ own purposes"
So, Facebook Companies can't use the info for their own purposes but can use it as Facebook-owned WhatsApp directs.