When a KB article is edited by a technician, actually the e-mail notification is like this:
The knowledge-base article TITLE has just been updated
Please review the changes here: URL
The end user receiving the notification does not know what change has been made, and therefore whether it is important to consult the article or not.
There are other ideas on this topic:
But I think that exposing a DIFF of article body would be not useful and understandable for common end user; and keeping a log of changes is not in the scope of this request.
So in this idea, I propose adding an optional field, available to technicians when editing the article, to briefly indicate the content of the change. If this field is filled out, it will be included in the notification email.
The knowledge-base article TITLE has just been updated
Changes summary: DESCRIPTION
Please review the changes here: URL
Storing this change summary in a "KB article history" is a possible further implementation.