The real problem is: whether you want to use or not, you SHOULD make sure others know this.If it's a public RSS feed, then is there really a problem with what's Apple's doing? They're just using content that's publicly available content and providing it to Apple users. They're not charging for it, nor are they redistributing content that's supposed to be behind a paywall.
To me it seems the email was just to let the publishers know that Apple is using the content that's already being provided and allowing the providers to opt-out if they wish. As long as Apple isn't claiming that they created the content (and giving credit to the creators) then I don't see what the problem is.
Assume this: You can install any software without agreeing EULA prior, while app developer could embed this EULA into help page, and assume you agree this EULA unconditionally as long as you use this software.
Remember previous U2 "gate"? (If I could call this) Thousands of users are angry with this force pushing. Apple failed this time. However they tend to do this AGAIN.
That is all.