Protocol just updated their story with this paragraph:
>Apple told me that its actual mistake was approving the app in the first place, when it didn't conform to its guidelines. Apple allows these kinds of client apps — where you can't sign up, only sign in — for business services but not consumer products. That's why Basecamp, which companies typically pay for, is allowed on the App Store when Hey, which users pay for, isn't. Anyone who purchased Hey from elsewhere could access it on iOS as usual, the company said, but the app must have a way for users to sign up and pay through Apple's infrastructure. That's how Apple supports and pays for its work on the platform.