Lin Yuan knew that the Zheng family would look for him. To be frank, the Zheng family simply wanted to find out his status.
After calling for the assassinations on Listen, the Zheng family had already consecutively lost two king-class experts. One of them was even a pinnacle king-class expert.
The loss of the pinnacle king-class expert was already enough for the Zheng family to be apprehensive toward Listen. Therefore, before the Zheng family was able to find out the Listening Heron Chamber of Commerce's backer, they wouldn't make a move on Listen first.
Since a pinnacle king-class expert was already dead, they would need to mobilize an emperor-class expert if they had to make another move.
The battle between emperor-class experts would involve Law Runes and power of law. It wasn't like the battle between king-class experts which could be controlled.
If an emperor-class expert was to make a move recklessly, things might go overboard.