USA TV in 2017
Yup this is a nationwide issue. Some stations will stop broadcasting altogether. Some will not be affected at all. But just under 1000 stations will be changing the physical frequency that they broadcast on. However, because ATSC provides virtual channel numbers, the channel you know a station by will most likely not change.
It's tough to imagine how much spectrum was originally set aside just for over-the-air TV broadcasting in the USA. Channel 1 was lost a long time ago. Next went channels 70-83. Then channels 14-19 are "shared" in major cities like L.A. and N.Y. Channel 37 was given to radio astronomy. In 2009 channels 51 to 69 became the 700 MHz band.
This latest round "gives away" channels 38-51. The stations broadcasting on those channels will now either go off the air, move to a lower channel, or "share" a channel. ATSC makes it possible for multiple programs to be broadcast on the same physical channel.