That depends on the app.
I have a couple of apps that are out there, right now, that use the Apple iOS notifications system (I write native Swift apps).
One of the apps, is the end-user one. That does not subscribe to external notifications. I only use the notifications system to badge the app icon, if there are things that need to be addressed. The badge is only affected, when the app is being run.
The other app, is an admin dashboard for that app (It uses a server-based system to manage user accounts). That subscribes to APNS, so we get alerted, when new signup requests come in.
The end-user app has a notifications panel in the Settings app, and you can specify that it not badge the app icon, but that makes no difference, in terms of privacy, because nothing is ever sent to the server.
The dashboard app actually registers the device ID, when registering for push notifications. Apple is probably aware of the device ID, and likely uses it, internally for stuff, but as an app developer, I only care about it, when one of the dashboard users signs up for push notifications. In that case, I store the ID into my own database, and use it to send push notifications to the device.
I suppose there may be some built-in OS services, that use APNS behind the scenes, but I'm not aware of them.
But Apple knows where all its devices are, and how to reach them (which is why it's a bad idea to buy a stolen iPhone). APNS is just an exposed SDK, to piggyback on it. I don't think there's any way to avoid them knowing where your phone is, unless you choose to use a [non-Apple] system that doesn't have any of those types of services.