When working with Managed Navigation when you move a navigation term you create a broken link in your website.
One of the new capabilities in SharePoint 2013 is Managed Navigation that allows you to model the navigation of your website using taxonomy. Not only does Managed Navigation allow you to use friendly URLs but it also decouples the navigation and URLs from the physical structure of your website. Should you need to rearrange how your website is structured and where your pages are stored it will have no impact on the search ranking of your website or the user experience.
The downside of using Managed Navigation is the fact that whenever you move a navigation term you create a broken link in your website. When working with Structured Navigation SharePoint 2013 tracks all incoming and outgoing links within the Site Collection and should a file be moved to another location all links are changed accordingly automatically. This isn’t however the case when working with friendly URLs. If you move a navigation term to another location in the navigation, you will create a broken links that you will need to track and fix yourself.