Update: DIRECTV STREAM Will Add 4K Video This Year

That's almost certainly much more exciting sounding than it really is.  There is very little 4k content on DTV satellite (or on the live streaming services that offer it) - basically a small amount of sports, some documentaries, and maybe some special events.  And that is what I'd expect to see, on a dedicated 4k channel or 2, perhaps with an additional fee.  None of the "regular" DTV content is available from the networks in 4k and there is no indication that will change anytime soon.  Even though ATSC 3.0 ("NextGenTV") supports up to 4k, I'm not aware of any content providers going past 1080p yet or making any noise that they plan to.  It'll probably happen eventually, but I wouldn't hold my breath.