Yang Qing mentioning the contract openly and promptly at that, was a deliberate ploy on his part. He wanted to gauge the reaction of the newcomers. While the parties present were made up of seasoned experts capable of concealing their emotions well, he still managed to glean something from it, which if his analysis was right, at least reduced the weight of what would happen next when the other parties arrived.
It would not be too long with Xia Ting having already informed Yu Gen that she was headed to the last location, making it here would be easy since she could use a large distance teleportation talisman.