Kindle is not a subscription service. The relevant clause would be about in-app purchases. But it wouldn't surprise me that Amazon threatened to pull off the platform, and more power to them. If I were Jeff Bezos I wouldn't be removing any buttons or links from my apps, either.
Netflix is a subscription service. Apple's been approving Netflix and Kindle updates silently while picking on the small guys because they could, many small guys left the platform in frustration.
