Looks like they're doubling back to cover some of the material from Feast and Dance that wasn't used year, with Euron and Aeron Greyjoy set to appear and Jaime apparently headed to the riverlands.
I see they will continue to waste our time with pointless subplots next season. No way this show ends in season 7 at this point, or this series ends on a cliffhanger.
Unlike the Walking Dead, the GOT writers can't go too off script and kill off any of the main cast that they want to. GOT is still following the map laid out by the author, while TWD can and will do its own thing which is why it has the potential to last much much longer as a series.