I also think this episode confirmed Jamie is going to kill Cersei. And only because of how badly they handled it! Unless they are misdirecting but I doubt it. We are believed that after sleeping with Brienne he suddenly in few hours does a 180 and goes bad again and is going to be with Cersei? It's an obviously very bad setup for Jamie to kill Cersei and they are thinking they are surprising us.Seems like there's a setup for Jamie to kill Cersei. I recall the prophecy about who would kill her.
The funny thing was the producers insisting in the behind-the-scenes that Jamie has chosen Cersei. All I could do was to shout at the TV, LIAR! If it turns out true, as far as I remember, this will be the first time that they intentionally lie in a behind-the-scene video. They are not supposed to lie in the making of videos!