I dont know, I kind of disagree with you guys.
If the show runners are going to go with some of the storylines that were initially thought as cut, Greyjoys, then there is no reason to think Stoneheart couldn't come back. It's also possible that Jaime finishes in Dorne this season and he continues his book story by going to the Riverlands. Which would make more sense in terms of bringing Gendry back, Brotherhood without Banners, and then Stoneheart as well to all tie along with how the book went, and somehow adding Brienne and Pod back into that as well. Also bringing back the Freys, Edmure, and Blackfish. I think its entirely possible and would still be a huge shock to show watchers because so much time would have passed. Now that I think about it, that could be an awesome season arc for next season, the Riverlands and the unresolved issues there. Who knows though.