Polling domains when attached to the network like this doesnt suprise me in the least. Apple's ecosystem has often been praised for its tight integration, and this consistent network connectivity is the result. Anybody who has worked with large scale services that rely on messaging services to ensure people get timely notifications and data, knows that you need services which are continuously polling endpoints to check and see if they have new information.

Organizations like Apple who service billions of devices cannot rely on a "push data to system only when something has updated" type of system, as such a system doesnt operate at their scale. They have to operate a system where individual clients are assumed to have an unreliable connection to the service, and where the client does the legwork of checking for new data stored in a centralized system.

This is what you are seeing in the article. Domains like [gdmf.apple.com] which govern device management, are where the declarative device management system is checking Apple's various databases to see if they need to update their configuration.