Yes, they can. They're just not allowed to link to their subscription page from within the app. If they offer in-app subscription purchases the pice of that offer should be the same or lower as outside the app:
"If you would like to make a subscription offer outside of the app, the same (or better) subscription price must be offered inside the app […]"
Some people misread this sentence as "you can't put a content app in the app store without giving money to Apple".
No, it means if you offer a subscription product, people have to be able to sign up for it through the app using Apple's subscription service. They can still let people sign up on their website, but they also have to let people sign up on the app, and they can't charge more even though Apple is taking a 30% cut.
What Apple is doing is worse than what credit card companies do. --At least with credit cards merchants can offer a discount for paying with cash.
No, it's fine. Section 5.11.2 of the Mastercard agreement notes that "A Merchant may provide a discount to its customers for cash payments". What is usually prohibited is charging an extra fee for paying by credit card.
The relevant text is in section 11, article 13 of the App Store Review Guidelines:
Apps can read or play approved content (magazines, newspapers, books, audio, music, video) that is sold outside of the app, for which Apple will not receive any portion of the revenues, provided that the same content is also offered in the app using IAP at the same price or less than it is offered outside the app. This applies to both purchased content and subscriptions.
I read it in the press release as being just about the price and not the fact that you _have_ to offer it. I guess I was wrong?
