I am pretty sure he does not need to rename the admin cp and mod cp. I have always had a different name for mine and I have never renamed them for the upgrade. Don't forget that their 'location' is defined in the config.php file, so I would guess that as long as it is correct in there, then vbulletin can find them.
I think he meant when it comes to uploading the updated files when you upgrade. They both have to have the same names so files get overwritten correctly if they need to be overwritten.