Users have to read & agree the new terms until Feb 8, else WhatsApp will delete your account.
The app collects a lot of metadata such as phone number, your profile picture, usage patterns (features you use, groups you’ve joined & status in Story format) & device data.
Updated policy says that WhatsApp may send you marketing material about Facebook companies, it will use your data collected from the app & other FB services for content suggestions, people recommendations & ads along with service improvements.
This will also let merchants communicate with regular users on the platform, it will let businesses integrate other services into chat app. So third-party apps might be able to read your communication on behalf of business you’re interacting with, an in-app video player may know your IP address. too