Update RoboCopy documentation with important notes

Clarify RoboCopy behavior regarding file copy reports and metadata updates.

Author: codefinite-vri

includes/storage-files-migration-robocopy.md

@@ -36,3 +36,9 @@ robocopy <SourcePath> <Dest.Path> /MT:20 /R:2 /W:1 /B /MIR /IT /COPY:DATSO /DCOP
 
 > [!IMPORTANT]
 > We recommend using a Windows Server 2022. When using a Windows Server 2019, ensure at the latest patch level or at least [OS update KB5005103](https://support.microsoft.com/topic/august-26-2021-kb5005103-os-build-18363-1766-preview-4e23362c-5e43-4d8f-95e5-9fdade60605f) is installed. It contains important fixes for certain Robocopy scenarios.
+
+RoboCopy might report that files were copied even when no data transfer was necessary. This behavior occurs because robocopy evaluates both file data and metadata changes when producing its output. To correctly interpret the results, review the file status in the command output:
+- Newer: File data is copied to the destination.
+- Modified: Only metadata is updated; file data isn't recopied.
+
+In both cases, RoboCopy might report byte counts as though data was transferred. This behavior can lead to confusion when validating copy operations.