I tried to address this in a response in a different thread
I believe that GDPR requires users to actively give their consent to use of data, and that it does not prohibit companies from collecting and using data so long as users give that consent. That’s why I won’t accept WhatsApp’s new T&Cs, because doing so would give them the consent they need to share data with FaceBook. As Facebook are saying (I think) that the new T&Cs do not involve a change to how they share data, it may well be that I had given consent previously without realising - my mistake