The only D+ benefit that the other couple will gain in the increased balcony discount of the extra $25 off the stateroom. (if you are not in a balcony u gain nothing). You will get D+ benefits and they will get their D benefits.
I had the same experience on Ovation HNL to YVR last week. Great reception in my cabin, a couple areas of the ship not so great but overall worked fine for me. I know that others on our sailing had difficulties in their cabins.
They must be able to clear those lines then as that is the route that they put up on a map at the top tier event and said the Ovation would be taking on her first Alaska sailing
Do they get exemptions, they said on board Ovation last week that she would be doing the inside passage from Vancouver on her first Alaska sailing of the season. Vancouver to Seattle.
When they haven't been filling the Navigator and she has some of the lowest per day rates around it will be a long time before you see Oasis class ship out of LA.