Linked text can be set to update automatically.

Also, the styles in your template can do the same. For the latter, go to the Templates and Add-ins dialogue (with your document open, press Alt +T,I, or click on the Template icon in the Developer tab of the ribbon (you may have to activate this in the Office button options). In the Templates and Add-ins dialogue, top left, uncheck the box that says "Automatically update document styles" if it is checked.