We are not party to every little change which the update will make. You see as much as we do in a search..
A Recommended Update.
"This update helps Microsoft make improvements to the current operating system in order to ease the upgrade experience to the latest version of Windows."
It only applies if the user is going to upgrade Windows 7 to Windows 8.1. It does not apply if the user intends to clean install Windows 8.1.
If you intend to neither of the above, it is quite safe to hide the update and forget about it. There will be no ill effects.
Microsoft see it as important because it IS if the user intends to upgrade to Windows 8.1 at some point in the future, and Microsoft assumes that users will do this. There is nothing more that can be said.. :-)