I just had the same thing - I had beta 5 installed and wanted to return to iOS 16. After going back to 16 I got this message during set up. Never seen it before in 13 years of iOS development.

Got it - use a CXHandle with a phone number and add a contact with that number

That means the API was first introduced in iOS 4 and was deprecated in iOS 16. It doesn't mean its deprecated in iOS 4 to 16 and will magically not be deprecated in iOS 17

There's no need to submit it for review in the first place if its not going into the App Store and not available to the general public

If an app is terminated then it won't get launched when it receives a background push, so you can't do it that way. However it is possible if a notification service extension is capable of getting the location, but you would have to request an entitlement from Apple. If you implement a notification service extension to intercept the push, the extension is capable of making a connection to your server. I don't know if the extension is capable of obtaining the location, you'd have to experiment and see if it is. Some extensions are limited in their capabilities but the notification service extension is capable of doing a lot of things. The problem is the push notification that the extension receives has to be displayed to the user. Unless you can get a notification filtering entitlement, that would enable the notification from not being displayed to the user. The entitlement can be applied for through the Apple developer account, you have to give a justification to Apple why you want/need it.

If an API is private then yes your app will get rejected from the App Store. As to whether iokit is private, it doesn't look like it for 3 reasons: 1) you can find documentation about it by googling, a private api has no available documentation 2) it doesn't say it is 3) Eskimo doesn't say anything about it being private in his comment here: https://developer.apple.com/forums/thread/719564

The same thing is occurring also with notification service extension. Run the extension on iOW 17 and all logging in it is duplicated just as it is in a call extension, run it on an iOS 16 device and the logging is as expected.

Presumably you have the carrier entitlement that enables the api to function?

Choose ad hoc distribution rather than developer distribution

No it's just not possible. And trying to send a silent push every 15 minutes won't work either

When I moved from a non M chip Mac to an M1 Mac I had huge amount of pain getting thing set up for RN. Too many problems to remember and list. However, I remember something about Ruby, the default version that comes with the Mac wasn't the correct version (too old maybe) to work nicely with RN. I can see a few mentions about Ruby above. Maybe google about that to see if that's an issue

I had to download the iOS simulator before I was able to use a physical device. Surely that must be a bug, otherwise its crazy insane behavior for physical hardware to have a dependency on the simulator before its useable.

P.S. I have another app where I am using a .framework within the app and also within the extension, why are there no problems when using a .framework in my other app, but trying to use a .xcframework in a similar manner does not work in this app?

A background push will never ever get delivered to the app if the app has been terminated. There is absolutely nothing you can do about that. If the app is in the background it should, however it might not if the batter level is low or several other undocumented criteria.

You can learn how to code for iOS from books and tutorials, but unless you do something like enroll in a programming course that teaches you the fundamentals and principles of design and code, then the chances are you won't achieve your goal to become a good developer, you'll be somebody who can create an iOS app but is probably designed like crap and implemented terribly and is working tenuously and will fall apart with a slight change. If it works as you intended maybe that doesn't matter to you, but you did say good developer was your goal as opposed to a goal of being able to develop an iOS app. Sorry to sound so negative, but it's just the truth.