Scope of Document Template editing

If I have several instances of docs all based on a particular document template and I make a change in the document template is that change going to show up in all the pages which are based on it?

It should show up in all new documents created after the change in the template is made.

Document templates are just documents that get duplicated when you invoke the menu item or toolbar. If you think of a Scrivener project as a folder on your hard drive with a bunch of sub-folders and documents, then a document template is just a document you keep making copies of. If you change the source document, it can’t affect the copies you made previously.