I read through WhatsApp’s new terms and I don’t understand what the big deal is. Isn’t it mostly about messages with businesses?
In the EU (and UK), it's some fairly minor changes to do with business messaging.
Outside of the EU, it is much more significant, merging your WhatsApp data with your Facebook data (including the phantom profiles FB create for users who don't have accounts). They can't do this in the EU (yet) due to privacy laws.