Why does Apple suggest registering for remote notifications “as part of your normal startup sequence”?

After reading the Local and Remote Notifications Overview, under "Obtaining a Device Token in iOS and tvOS"

"In iOS and tvOS, you initiate APNs registration for your app by calling the

registerForRemoteNotifications

UIApplication

and the API Documentation for requestAuthorization(options:completionHandler:),

"Always call this method before scheduling any local notifications and before registering with the Apple Push Notification Service. Typically, you call this method at launch time when configuring your app's notification support. However, you may call it at another time in your app's life cycle, providing that you call it before performing any other notification-related tasks."; emphasis mine

I am wondering why prompt the user on startup to give permission for notifications? The user has barely used the app let alone being able to see the value or have a strong incentive to allow for push notifications.

In addition, how does Apple recommend you associate the device token to a user account in this case?

I am looking to get a better overall understanding as it is not clear to me why Apple would offer such advice at all.

Update

Looks like an older version of the guide, stated that “Device tokens change when the user updates the operating system” then continued “As a result, apps should always request the current device token at launch time.”

Which made sense at the time, since the device token could change without the app noticing.

Is that still the case then? Does the advice still stand or is the guide out of date?