If we’re going by how the novel is constructed and politics in Westeros then Sansa actually won’t inherit. One of the running themes in the book is that the people who are crowned or inherit have very little say politically and it’s the players around them who truly move the pieces around. So by the logic that some fans have that Sansa is “learning the game politically” ( which is also an arc very much inflated by the fandom) then it would follow that Rickon would rightfully inherit as tradition goes but Sansa would be the one who does the ruling through him. I know people are obsessed with “Queen Sansa” but I personally don’t see Sansa training to become a ruler, I see her learning how to play the game and those are two very different identities in Westeros and the novels. And the theme of the novel is that the north is actually now actively looking for Rickon to name him their little lord, they’re not going to pass him over simply because Sansa “knows how to play the game politically”. I personally wish Westeros was more progressive but the North isn’t and regardless of the fact that Rickon is probably a little wild by now, no one is going to pass him over to give ruler ship to Sansa. I mean Rickon being wild is not a reason to not have him inherit. Joffrey was a sadistic bastard and no one thought to pass the title to Myrcella or Tommen did they? Inheritance only passed when Joffrey died so unless Sansa is planing to take out her little bother then inheritance will pass to Rickon regardless of his wildness etc…
I think there’s a slight misunderstanding here about what most readers mean when they discuss Queen Sansa?
The idea of “Queen Sansa” isn’t necessarily rooted in the idea of Sansa as the de jure Queen in the North so much as the idea of Sansa as the de facto ruler of the North (and potentially the Vale and the Riverlands, etc.). While supporters of the idea of a Queen in the North do advocate the potential of an ending in which Sansa is the ruler in both fact and name of the North, in the sense that we believe in the feasibility of a Queen in the North end game, what we are really discussing is the fact that, by the end of the series, Sansa will be the key decision maker and holder of power in the North.
And there is quite a lot of foreshadowing for this development in Sansa’s character progression - as early as AGoT we have Sansa talking about “when I am Queen” - and Sansa being placed in a position in which she learns what Queenship means from various other women in power such as Cersei, Margaery, Olenna, and Lysa. Moreover, I think the transition from “soft power” to “hard power” will be key to Sansa’s freedom from Littlefinger. By eventually choosing to embrace the “hard power” that her name and position entitle her too, Sansa would be asserting her identity as Sansa Stark, the daugher of Ned Stark, against Littlefinger’s insistence that she is his daughter, Alayne Stone. So while I agree that Sansa is currently training in the usage of “soft power” like Littlefinger and Varys, I am fairly certain that a return to “hard power” will be critical to her narrative (whether it be as Lady of the Vale, Queen in the North or Regent of the North).
There is also an overarching trend of women entering positions of power throughout the series, even if the path isn’t a smooth one. As of ADwD, the rulership of most of the 7K has already been touched by the hands of women - Margaery and Cersei in King’s Landing, Arianne in Dorne, Asha in the Iron Islands, Lysa and now Sansa in the Vale, Daenerys in Essos. Regardless of his other comments, Littlefinger did correctly discern one thing - chaos is a ladder, but it’s an ever shifting one that allows power to fall into unexpected hands and can lead to a drastic shift in a realm’s political landscape and trajectory. There is most certainly significance in the fact that many of the characters recognize that the War of the Five Kings is over, but the War of the Three Queens has yet to begin.
Characters like Tywin Lannister, Kevan Lannister, Ned Stark, and Robert Baratheon, who represent the patriarchal status quo of pre-GoT Westeros have all been killed by the chaos of the game. Traditional values and social structures such as guest rite and kingship have all but completely broken down. The Iron Islands, another bastion of tradition, had a king who desired to break tradition by passing his throne to his daughter rather than to his brothers or son. There is a woman secretly studying at the Citadel. The Targaryen throne, which legislated the loi laique that women could not inherit the Iron Throne, is being held by a Dragon Queen - and there is no reason to believe that she will step down for the “legitimate” male Targaryen heir. Even the status quo of Essos has fallen apart - the ancient slaver cities being uprooted by a Khaleesi who refuses to join the Dosh Khaleen upon her husband’s death.
Regardless of the conservatism of the North, the narrative trajectory seems to hint that the Northern lords may not have much of a choice as to whether the North is ruled by a King or a Queen.