Woody Leonhard's article said it was an optional update. But, like you, mine is categorized as "important".
I have grown more and more concerned about what Microsoft categorizes as "Important" updates. I suspect they may be looking through the lens of what is important to Microsoft more than the lens of what is important for their customers' computers.
KB3035583 which enables Microsoft adware is a stunning example. There are various reports, but KB3035583 sure showed up on my computers as "Important."
Microsoft is taking advantage of a respected institution -- Windows Update -- to promote things and may not be paying enough attention to non-Windows 10 things. Windows Update is considered by most as an essential if not integral part of what you do to keep your Windows system safe. These kinds of mistakes and moves damage this, what should be treasured reputation.
I understand they are about to take Windows Update behind the curtain in Windows 10 -- meaning if I understand correctly, the user (read "owner") of the computer will not be in the Windows update loop, meaning it will take place without your even knowing it.