UIWebview to WKWebview migration

The App Store doesn't accept UIWebView apps, the WKWebView was submitted in 2016, maybe before, I am not sure. So you should aways avoid using UIWebView in your app. Some features are not present in WKWebView for safety issues.

You can search the Developer app for sessions. Doing so does not reveal any UIWebView-sessions. If you have questions on moving to WKWebView, I encourage you to try to get a lab session, or ask your specific question here on the forums.