You can disable the iCloud sign-in from popping up with the following defaults command: sudo defaults write /System/Library/User\ Template/Non_localized/Library/Preferences/com.apple.SetupAssistant DidSeeCloudSetup-bool TRUE. Iâve also posted this in a script available here in my GitHub repo.etting com.apple.SetupAssistant.plist in /System/Library/User\ Template/Non_localized/Library/Preferences/ to include the key DidSeeCloudSetup with a Boolean value of TRUE will stop the iCloud login from automatically coming up for new users.