Apple is phasing out UIWebView, which is used by developers for integrating web content into an app in a quick and secure manner. Apple is replacing UIWebView (and WebView) with WKWebView, an updated version, as UIWebView has been deprecated.
Apple originally told developers that app updates with UIWebView would no longer be accepted as of December 2020, but Apple is now providing additional time for developers to adopt WKWebView and has extended the deadline period. There's no new deadline in place at this time, with Apple planning to provide an update at a later time.
Along with the deadline extension, Apple today also informed developers that App Store server notifications are able to provide real-time updates on a subscriber's status, allowing for customized user experiences.
There's an option to be notified when a subscriber auto-renews and an option that lets you know when the App Store begins asking users to agree to a new subscription price, letting developers send reminders about a service's value.