Just FYI, some issues that occur on macOS 10.15 (Catalina) and iOS 13 have indeed been fixed in our GitHub repo.
System font label rendering issue on macOS Catalina. Corresponding issue: https://github.com/cocos2d/cocos2d-x/issues/20076
VideoPlayer error on iOS 13 as MPMoviePlayerController is removed, corresponding pull request is https://github.com/cocos2d/cocos2d-x/pull/20085
WebView error on iOS 13 as UIWebView is removed, corresponding pull reuqest is https://github.com/cocos2d/cocos2d-x/pull/20098