In case you missed this, the BBC has started a very limited trial of 4K HDR material (interestingly not bothering with mere 4K and jumping straight into the boiling cauldron of competing standards that is HDR).
This trial isn't via conventional broadcast means. Instead it comes to you via the iPlayer, or at least, iPlayer technology. And it makes a very important point: why bother with broadcast now anyway? Why even bother figuring out how to pump this stuff over the airwaves?
Well, perhaps that's taking it a bit far. But the simple fact is that today — and increasingly so in the future — innovation is going to be through the internet. The internet doesn't impose ancient standards, and it's completely adaptable to new ones. Virtually any smart device (computers, phones) can download software to decode practically any format.
I'm not saying that we might as well turn off broadcast TV today, but (and this is from a completely biased position where I have extremely fast broadband) IP video delivered over the Internet will be pervasive and ubiquitous within a few years. Series like WestWorld and Planet Earth II in 4K HDR will make sure of that.
The exciting thing is that neither the BBC nor any other broadcaster needs additional infrastructure to distribute 4K HDR material. If they wanted to, they could send this new format to everyone, tomorrow, subject only to arrangements with streaming providers.
Unless, of course, if you live in a rural location with only around 1.5 Mbit/s or less, as many do, then please disregard all of the above.