Since the widget macro function is to fetch something from the web and display it in real-time I can tell you that if you change something on the source document it will be reflected in the widget.
However, according to the documentation of the macro, we are advised to use the Google Drive macros instead. You can check this information here:
The Google Drive macro is another plugin which the instance administrator will need to install if not already present. You can take a look at how the macro works here:
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