His reply really only covers half of the relevant changes. The other parts are where they now require in-app purchases for any "premium content" which is accessed by the app and forbid links to a website to purchase content.

Subscriptions have nothing to do with the Kindle app at all and only partially relate to Netflix. The larger conflict with these apps and the new TOS relate to online purchases of content rather than subscriptions.

This response also isn't very useful because it is a lot more important how the TOS are interpreted in practice by the App Store reviewers than what the original philosophy for the rule was.