Apple has opened up its Apple News Format for all publishers, extending the tools to publish media-rich stories formatted and optimized for the iOS News app. Prior to its extension, Apple News Format was only available to select publishers, while others were restricted to more basic RSS imports.
Once a publisher opts to upgrade to the Apple News Format, they will be greeted with the following dialogue describing the benefits of switching and indicating that the move away from RSS is permanent:
With Apple News Format, you'll be able to create articles optimized for iOS 9, view engagement analytics, and earn revenue through iAD. Once you publish in Apple News Format, your RSS content will no longer update.