People are freaking out about this quote in the trailer, thinking it’s foreshadowing Sansa turning against Jon, but it’s a quote from book one, said by Eddard to Arya:
“Let me tell you something about wolves, child. When the snows fall and the white winds blow, the lone wolf dies, but the pack survives. Summer is the time for squabbles. In winter, we must protect one another, keep each other warm, share our strengths. So if you must hate, Arya, hate those who would truly do us harm. Septa Mordane is a good woman, and Sansa… Sansa is your sister. You may be as different as the sun and the moon, but the same blood flows through both your hearts. You need her, as she needs you… and I need both of you, gods help me.” - Eddard Stark
Eddard was telling Arya the pack must stay together. Arya is the lone wolf, not Jon.
My prediction: Arya will reunite with the others at Winterfell but will then want to leave. This is Sansa asking Arya to stay. The pack (the Starks) are stronger together.
AND THEN THEY’LL KILL LITTLEFINGER!!!!!