When you’re working with a team on a project using xrefs, it can be really handy to know when somebody makes a change to a file that your current drawing references.
Fortunately, a relatively new feature in AutoCAD LT makes it quite obvious that a referenced file may need to be reloaded. (Sorry to say, I don’t remember exactly when this came in. Anybody? Although I’m pretty sure it was in AutoCAD before it was in LT, so they may be two different answers.)
The notification bubble even provides a link that you can use to reload the affected file without going through the Reference Manager. You can turn these notifications off with the system variable XREFNOTIFY, but personally, even when I’m the one who made the change, I like to use the bubble to reload the drawing. It feels like the fastest way to get to the file, and it helps me remember to actually reload it.