Technically, this means Jon is the rightful 'heir' to the throne, but what we've known about Jon throughout the entire series is that he doesn't want to rule. He just wants to save everyone from the dead army.
But, like it or not someone will win the war at the end of the season, claiming the iron throne as theirs.
But what if there was no iron throne to sit on?
There is a new theory circulating online that suggests after the battle in Winterfell (episode three), whoever is left alive will flee to King's Landing.
We can assume they have lost a lot of the weapons made for the battle against the White Walkers, and will need more. Lucky for them, there's a large chunk of Valyrian steel sitting in the middle of Kings Landing - the iron throne.
Aegon The Conqueror created the iron throne from the swords of his enemies. He used Dragonfire to melt the swords down.
In the novels, the sword edges are sharp, with the idea being that a king should never sit comfortably. Author George R.R. Martin even said the chair was created by blacksmiths, not craftsmen. It is not meant to be comfortable or functional. It is a symbol.
What better way to smash that symbol than to melt it down and use it for a better cause anyway?
THAT'S the kind of twist we'd love to see at the end.