Thank you, but my question was more about the connection between email 1 and email 2 in that chain. Unless you're saying that Apple had already revoked the exception by the time these emails were sent?
It was allowed under the old rules, then the rules changed, then the Amazon ad these emails were referencing game out. So at the point of these email the Kindle app was out of compliance with the App Store rules, but Apple was allowing it as an exception because they viewed it as a promotion of Apple products. This ad changed their view and now though that the Kindle app on iOS was a promotion of how easy it was to move to Android.
I don't read it that way (most of your post I agree with though). I think the point was that before this email, Kindle devices had their own customers, and Apple wanted Kindle as a feature on their products to increase the appeal of iphone/ipad. But eventually those customers started doing all their "kindling" on their apple devices, so now from apple's perspective they think "we are providing you customers/making you a market, pay us". This is what the whole second paragraph is about.