That is the exact same message I see on my J3 connected to my H3. Did I finally answer your question?
Yes. So, I guess we can now assume that YouTube is definitely
not coming to the Hopper Duo or Wally, since Dish is putting the same message on those models that they put on Joeys, when trying to access YouTube. On the other hand, Scott never did give a firm "no" for either the Hopper Duo or the Wally like he did for the Joeys. Darn those non-disclosure agreements!
Either way, I still say that it is not very helpful for Dish to put a message on screen suggesting to try the command again, if it is a feature that Dish knows for sure is
not coming to those receivers. That seems sort of cruel, telling people to keep trying it, knowing that it is never going to work for them.