The premonition the Dreamweaver gave you also mentions about a Butterfly plotting, right? Maybe lady butterfly's been traveling from world to world and did something to anger that goddess. In fact, I think that would make even more sense than the Tang Wei theory, considering how much time has passed since he fell into this world.I know the meaning but
"her arrival will cease life, her gaze will shatter the sky. She's inevitable. She is the end."
"A vision of our world destroyed. Land was broken, sky was shattered, mountains had collapsed and oceans had dried. No being was left alive: no human, no beast, not even a single bug or ant." Notice the beast meaning Caihong wouldn't be spared
The theory also makes Shen Long Mu main madness and grief entirely unrelated to us or anything from the POMA world making it far less impactful and useless narratively speaking. There are countless and countless worlds spread across the universe with Dragons in them. Why would Yichen killing a grain of sand of them make her as Dreamweaver put it "She's back... Each time that she wakens, her mind slips further into madness. Each time that she howls in torment, worlds collapse".
Now if you switch a dragon god with a human god who had her daughter stolen by Tang Wei and sacrificed in a ritual? It makes her actions and the effects that Dreamweaver saying her name caused far more sense along with her madness and grief. It ties well narratively speaking
Sounds crazy, but I even think she was the one who planted that vision of the world's destruction in Yichen to make him kill the dragons. And if she did it with Yichen, who knows if she’s been doing the same in other worlds too.