https://www.gamespot.com/articles/dont-expect-a-big-new-xbox-one-dashboard-update-so/1100-6453639/

Xbox corporate VP Mike Ybarra has set expectations for Xbox One dashboard updates. Responding to a fan on Twitter, Ybarra said you should expect "small adjustments" to the UI in the near future instead of "big changes."

It's no big surprise that major dashboard updates would slow down, given that the holiday season is ramping up. Microsoft doesn't historically release major UI updates in those months because so many new players are coming online and significant changes could lead to confusion.