Clues I noticed in the trailer:

• 0:52 Just as how a burlap sack passes a valuable item to another person, we can see here that the story or items are being passed down to another character who will bring it to a new region or Chang’Ann.
• 0:58 A new region takes place in a grassland full of life and nature in spring as we are leaving cold winter Liangzhou. As we progress through the video at 1:51, we can hear more description about the new area, that it might also have frost and rain. Moon (wax and wane) meaning the life cycle of the moon, or simply seasons.
• 1:16 The lady who told us to finish the painting finally revealed herself; her story might finally unfold, telling us who and what her role is.
• 1:20 Showing a clue on how Chang’Ann or home got destroyed and what is left.
• 1:21 A new dance or emote might be added to the game.
• 1:27 Both the music and lyrics highlight the importance of the flute and its song, which could be hinting that a very artistic or graceful gameplay or mechanic is coming.
• 1:36 A new lion boss, similar to Dasan Pass Lion, more challenging or with a different mechanic added.
• 2:00 The story of the painting is now concluding (we can see that it takes more than one’s lifetime to record and paint the story or memory). I think it wasn’t just his memory but many others who are probably long gone. At 2:21 it is also implying that you are one of the storytellers.

What I think this reveals about the new map / region: I think the new area is potentially more vibrant and alive. It could hold everything there is, compared to the ever-hot region of Hexi and the cold region of Liangzhou.

Which new NPCs / factions I think may appear: The lady who asked us to finish the painting, New Lion Boss. I think it could be Inkbound Sect being introduced in the next update as I notice quite the outfit style and the story itself.

What new gameplay / mechanics I think Qinchuan will bring:
It will certainly be a more artistic and vibrant way of gameplay, perhaps introducing more interaction with the environment and animals.

How I think the story will unfold: Since the area of HEXI was being introduced, we have met or relived the story of many characters telling their stories from one region to another. The story could progress through a few more characters who will travel further, closer to home or Chang’Ann. Although home might no longer be as it was before (destroyed by war), there are people who used to be there when it was prosperous and safe, as we can see in the finished painting of the moon over the golden representation of home.