For context of why there were some flashbacks, she was the one that planned everything from the beginning, our meeting with Scar and possibly our meeting with Camellya, Aalto and Encore (maybe) if we get a companion quest with her, we may learn something more interesting and her part in the story Edit: forgot about something, this conversation is way before we even meet Jinhsi, probably in the moment we woke up
I don't think she plan it. Rather it is a test for jinshi so it's likely that Jinhsi plans everything. in 1.0. Probably, the plan that Changli came up with is the relationship between Jinhsi and Jue. Every events unfoled at that dragon island is probably what she planned. That's why she stayed behind and let Rover and Jinshi battled Jue. This speculation is also hinted by her last move in the trailer, when she takes the black piece that reveals the dragon island. So basically, she already made her move years ago. I also believed that's why she is Jinhsi master.
It isn't as good as Jiyan's but man does this showcase really tie into the in-game lore. This showcase really displays how Changli worked behind the scenes to have everything in the first few chapters of the story fall right into place.