I have been there.... and I am aware of that link. BUT...its fairly new and was put up with the hopes of avoiding some of the discussions and threads here.
I hope Dish is paying you well for being their pied piper.
My point is simple in all of this... their receiver specs are buried in press releases, and obscure docs that very few typical consumers would bother to dig up before agreeing to terms of their contract. It says 4K, so "most" people can safely assume it will transmit the 4K signal to their TV, and they can view is successfully... but, if you read through this thread, you will see that there are a few caveats.
To take it even a step further--their techs and CSRs have no idea what the difference is between 4K and 4K HDR and what receiver supports what. I spent 2 hours and made 2 seperate calls to get to this point. Others have done similar, and imagine the numbers who have called but have not posted here. So, after much wasted time on the phone, the same thing happens--people come to the conclusion that the 4K Joey is not compatible (but no one reaslly knows why--it just isn't). Even your link mentioning the HDR feed for the Olympics and channel 147-05 says a Hopper 3 is required, but it doesn't say that a 4K Joey will NOT work. Most people with a Hopper 3 and 4K joeys will assume they can get the Olympics feeds on remote boxes....after all, it doesn't say that they don't work.
It states that a Hopper 3 is required to view the feed, and guess what I have a Hopper 3, with a 4K Joey attached. The statement is vague and they should change the wording, so its a bit clearer to the average consumer/client. A quick mention on that page that states the 4K Joey is not a compatible receiver will save people alot of headaches and wasted time.
I feel like I have already spent more than enough time trying to make my point here, and its unlikely that I will comment any further.
No worries... the next time I have a 4K issue, or need technical related info regarding Dish, I will be sure to contact you first.