That piece of the ending seemed designed to make Sansa Stark fans happy because it doesn't make too much sense outside that context.
You're spot on there. Sansa's "redemption arc" is to me probably the second silliest bunch of nonsense in the show after the Dany/Jon love affair and cliff drop to madness.
Since they dressed her in black to look bad*** at the end of Season 5, this is what’s happened with her:
--Basically tricked by LF and sold off to Ramsey.
--Raped and abused by Ramsey in her own home. Can’t call for help, doesn’t lift a finger to try and kill him.
--Needs saving by Theon of all people, who was a tortured wreck by then in his own right but found courage, unlike her.
--Finds Jon at the Wall prior to the B of the B. Tells Jon to listen to her when planning the battle, because she “knows” Ramsey. Meaning she knows he’s cruel, devious, etc. Hardly inside information there.
--For some idiotic reason that the show never explained, she does NOT tell Jon that LF arranged for the Vale’s mounted armies…thousands of heavy cavalry, are on the way. You think if Jon knew that it would have altered his plans somewhat for the coming battle? Maybe hold off a day or so and wait for them? Or strategize differently?
--But no, she says nothing, and instead looks all smarmy and smug as the cavalry thunders in…AFTER about 90% of Jon’s forces are slaughtered.
--“Kills” Ramsey finally. After he’s beaten nearly to death by Jon and chained to a chair.
--Gets credit for outthinking LF. When they go the whole season showing her conflicted, scared of her sister and jealous about the attention Jon is getting. The light bulb finally goes on after Bran tells her everything he knows. Arya of course actually kills LF.
--This season, immediately gets snarky with Daenerys, whining about food rations when if it weren’t for Dany’s forces, Winterfell and what’s left of the north get run over by the WW in about five minutes.
--Hides in the crypt during the battle while Jon, Arya, and Daenerys who she’s been complaining about, are out fighting.
--Gets told in confidence about Jon’s lineage, waits maybe three minutes before running and telling Tyrion.
--At the council in KL she demands an independent north, speaks of an army of thousands that laughably shouldn’t exist after the wars vs. the Lannisters, Boltons, WW and with most major houses in the north completely wiped out.
--Is crowned queen of the north, is cheered by a room full of old men apparently.
This is earning redemption?