They've also got a very spicy rematch coming in Week 13. It was a good enough matchup, in fact, that it was flexed to the 4:25 p.m. ET game on CBS.
Moving out of that spot are the Texans and Patriots, a previously awesome playoffs rematch that looks pretty "meh" now that the Texans are terrible. (Don't get me wrong: Case Keenum and Andre Johnson are fun to watch, but Chiefs-Broncos has much bigger implications.)
It's possible that Chiefs-Broncos could be flexed into the Sunday night game again, but as of right now that hasn't changed.
There's lots of politics that goes into these changes (all of it well above my pay grade) and you can guess that the folks at the mothership don't want to give up a Peyton Manning rematch against Kansas City, especially one that could be for the rights to homefield advantage in the AFC and an AFC West crown.