According to the FileSystemWatcher documentation (see the quote below) when moving a folder OnChanged or OnRenamed must be raised.
https://msdn.microsoft.com/en-us/library/system.io.filesystemwatcher(v=vs.90).aspx
...To be notified that the contents of folders have been moved or copied into a watched folder, provide OnChanged and OnRenamed event handler methods as suggested in the following table.
But it doesn't! At least with my .NET 3.5 C# application. Can somebody confirm it?