I think there is a possibility that Young Master Yue (Now Elder Yue) and Yun Que fell in love. She must have confided in him about her identity and struggles, but she knew that she had to go back to Wufeng. They must have spent some time together off their problems for a while and then Young Master Yue let her go out safely without being caught by the Gong family.
However, as Wufeng knew that it's impossible to come back alive from Gong's, even though Yun Que provided whatever information she could, they must have tortured her to get the real truth out.
The revelation about her falling in love and that the person from Gong family willing let her go, must have made them kill her for her breaking the rules of Wufeng. And as those people from Wufeng knew Yun Que was close to Yun Weishan, they took advantage of that and led her to believe the Gongs did it so that she will be even more willing to avenge her. They would also tempt YWS by telling her that her reward would be freedom.
But then now that Young Master Yue and YWS have kind of recognized each other through Yun Que's bracelet, maybe later he will tell her the truth and YWS will get to know the reality. And finally she stops supporting Wufeng. Now that she knows the truth behind Fortnight Flies poison, she doesn't fear for her life anymore.
And as we've seen from the trailers, during the wedding fight face-off, everyone's facade has fallen. Shangguan Qian goes with her raven. There's a bloodbath. GZY being attacked by Ziyi, Jin Fan perhaps dead ? But YWS is along with GZY and doesn't go with her raven. HYS has that defeated demeanor while kneeling down looking at the Gong Mansion. Maybe he knew that now there can be no reconciliation between YWS and him, as they both would be on different sides.