I think Apple is smart enough to know how to spin it if Facebook or Google left the App Store because of privacy issues. Some users would be annoyed at Apple, sure, but I would bet many users would see it as a Facebook/Google problem. I didn't hear people blame Apple for requiring listing what data is being collected when Google started not updating their apps and warnings started appearing.
This isn't about privacy or user data, it's a disagreement over how revenue is shared.
So rather than this sort of wording from the article: centers on the iPhone data of millions of people and whether companies should be able to track
We be read something like this: Facebook and Google go to war with Apple over revenue sharing agreement.
When one or another of them does things that changes who gets what sized slice, the others get upset.
There’s one big pie of US GDP. That doesn’t mean anytime someone gains or loses revenue that they are sharing it with someone else. Or at least there is no utility to be gained from that statement.