If your on a high speed, unlimited connection, Microsoft updates should be installed as they come out to insure you have a more stable and in most cases secure computer.
But many people (AT&T I am talking about you) have low bandwidth, low data cap plans that price gouge you and / or throttle your speed after you hit their cap (22 gigs if your on a AT&T “Unlimited” plan).
So if your a Netflix / Youtube junkie with 5 other people on your “Unlimited” plan most of your data is maxed out by the end of the month. But Microsoft makes no real effort to help you by letting you choose what to install (or not install). So your Internet data costs are now determined by Microsoft and not by you.
Via: Engadget
https://www.engadget.com/2017/03/19/windows-10-to-push-key-updates-on-limited-data-plans/