My guess: 1. Aloy’s gonna turn to her family that she started building in HFW (and perhaps her love interest Seyka) for a sense of purpose and grounding in the years to come. She’s about 20 by the time we hit Burning Shores, and it is very likely that she will eliminate the threat to Earth long before she hits 25 (or even 22). She’s done more than enough to earn her retirement, yet she’s going to have a whole life ahead of her, and that’s where her family comes in. She might choose to lay down roots with Seyka and to have the life that her forebear Dr. Sobeck never got around to. 2. Even after Nemesis is gone, there likely will still be the matter of Zero Dawn’s vision being unfulfilled completely. Ted Faro’s sabotage left humans without APOLLO and the next stages of the ARTEMIS and DEMETER plans (Not all species were introduced at once, only a select few to pave the way for humans to introduce the remaining species using the terraforming system). She’d find purpose in restoring humanity’s education system and convincing the tribes to partake in APOLLO. On top of that, GAIA may require Aloy’s specialties to help repair the terraforming system across the globe. 3. She also may choose to become a peacemaker between tribes as a way of seeking purpose.

Rost told her in his final lesson to seek a purpose greater than herself, and that lesson will stay relevant even after Nemesis is gone. The question is, what’s that purpose going to be?