The system will not be able to automatically update that change; you will need to do it manually. I mean, thinking about it, it's practically an impossible feat, right?
Viewing post in Ultra Localization | RPG Maker plugin comments
I still don't quite understand how the plugin works. So for example, I have a message that says Hello, then if I export all the message to a file and translate directly on the file to Hola, the game will automatically change the existing message to Hola? Or do I need to do something else to the messages like replacing Hello to something like {code123}?