This feature will be rolled out gradually in the developer preview, so you may not see it immediately on your device, but should
build your apps accordingly by removing background services.
For all intents and purposes, this is the same software that the public will receive when iOS 11 is launched later in September.For developers it's the final piece to the iOS 11 puzzle, letting them
build their
apps in the final
build of the platform, and prepare their
apps accordingly for their own public releases / updates.