The documentation for the defaultPath property of NEProvider is as follows:
This NWPath object contains information about which physical network interface will be used by connections opened by the Network Extension provider. You can determine when this physical interface changes by observing this property using KVO.
However, I have noticed that it is deprecated as of iOS 18.
Is there any existing replacement for this functionality since it has been deprecated, or is a new replacement on the horizon? This is very useful for network extensions in order to detect changes to the network, for instance when moving from WiFi to mobile data.