How about Notre Dame and Michigan last week? Or the Masters this year?
The Masters only did a hole or two from fixed camera positions, the whole production wasn't in 4K so watching that channel was not even close to a substitute for watching the real coverage. Golf will probably be the last sport to do a full 4K broadcast because the playing field is so large, there are so many cameras, and some of them are handheld.
As for NBC's Notre Dame games, they may have addressed that with their affiliates somehow - and this may have had something to do with why Notre Dame games were carried in 4K two years ago, then not carried last year, and now are back again. Maybe NBC had some pushback from them and had to come to some sort of arrangement?
Not saying its impossible to do, but the affiliates are doing to demand compensation, and that will make it really difficult for the networks to do NFL games in 4K unless/until affiliates can carry games in 4K. I could see room to maybe do a few games here and there that are carried on O&O stations since there is no one to complain, so maybe people in markets like NYC or LA that have O&O stations might get one of their games carried in 4K and subject to blackout in the rest of the country...