Squiz Matrix will automatically update links if the page asset you are linking to is moved.
It is important to link to the page asset in the WCMS rather than the url of the page. That way, when the page asset is moved, your link will update automatically. If you link to a url you will get a broken link when the page is moved as the url of the page will have changed.
If the page you have a link to is deleted, you will not be alerted so it is important to review your web content regularly.