I have a feeling this one's not going to go as expected.
For one thing, unlike the difference between SD and HD, the difference between HD and UHD won't be perceptible to many users. I can barely tell the difference between 720p and 1080p content; what do I need with UHD? This will be like the audio market, where many users are happy just to have a stereo with cheap speakers, and only the audiophiles spend the big bucks to get the better speakers and receivers. I think that when push comes to shove, a lot of potential users will look at this new system and say "who needs it?", particularly if it comes with a high price tag.
But an even bigger problem is that I think you are going to see some resistance to allowing TV receivers to access the Internet. It is becoming far more frequent for hackers to target the "Internet of Things" and some of the more widely reported hacks have been against TV receivers. I doubt you'll find many people who would say they want their TV to spy on them or track their viewing habits, yet an Internet-connected TV can do both those things. About a year or two ago I bought a "dumb" HDTV because I feared they wouldn't make them anymore, and I know of a guy who bought a "smart" TV but absolutely refuses to hook it up to the Internet, out of security concerns. I don't think the hack attempts on TV's are going to stop anytime soon, and for some people the idea that a TV might have a microphone or camera built in sounds too much like "big brother." There will always be stupid people who just don't care, like a couple guys I know who insist on using the same (insecure) password for every single online service they visit, but if major hacks start causing people to lose significant amounts of money or privacy that could change in a hurry.
As an example, the first time some guy dances naked in front of his "smart" TV, or has loud, graphic, passionate lovemaking that is captured with the TV's microphone, and it gets posted online (or a hacker threatens to do so unless ransom is paid), people are going to start disabling those Internet connections to their TV's.
Then there is the idea of targeted advertising. Targeted to whom? This could become a big issue in a place where a TV is shared by multiple users, at least among viewers that don't block or skip ads. I hope the people who are promoting this realize that if you turn a TV into a computer, you run the risk of people running sideloaded software that allows easy ad skipping. If ads come from an Internet source, all you have to do is block connections to the ad servers, and presto, no more annoying local ads (and local ads in small markets are the worst, since they are generally a "hard sell" with no production values). Keep in mind the law of unintended consequences; there are a boatload here.
I already am so annoyed by local broadcasters that sometimes I wish they'd all just disappear. The only thing they were ever really marginally good at was covering local news and weather, but nowadays we just read that online as it happens rather than making an appointment to watch a local newscast. And I think that may be the ultimate failure of ATSC 3.0 - by the time it is fully deployed, no one will care, because those with Internet connectivity will be watching everything from online sources, where the video is not defaced by local weather graphics and ad scrolls and similar crap. Our local Fox affiliate is a prime offender here, and more than once this past year I've waited a day and watched a Fox show online rather than having to put up with their defacement of the signal (not that I watch anything live anyway; I always PVR it and watch it at my convenience). If you look at a network like The CW, that is targeted more toward younger viewers, I would bet that they are viewed online as much as over the airwaves (particularly because in many markets they are either not available, or only available in SD).
People really aren't clamoring for better OTA TV. More and more, people are looking past OTA. To promote a new TV delivery method now might be akin to sending a crew out to apply a fresh coat of paint to the deck after the Titanic hit the iceberg.
I may be wrong, but I suspect I'm not.