Except that Service Worker support is a prerequisite for supporting the standard Push API, and push notifications are probably the most common usage of Service Workers. So it's a reasonable question.
Safari on the desktop has supported push notifications for a couple of years, with no indication they will be coming to iOS. I assumed go was referring to those push notifications, and not a different type of push notification.
Offline support is the core reason for Service Workers and using the offline capabilities is literally a prerequisite for handling any other events from additional specs.
