When this is associated with the upcoming retirement of Meng Hong, there is an overall feeling that the Sect Leader might, before resigning, try to resolve some longstanding issues all at once within the sect.
Chu Zuoshu likely knows about this situation, but considering he's due to be the next Sect Leader, he would most definitely be happy to see these things come to fruition. He probably wishes for Meng Hong to shoulder all the blame before retiring.
Then, he would ascend to lead the sect free and clear of these issues.
It's likely because of this that nobody from the Reward Virtue Hall was sent to investigate the matter of the Spirit Stone Mine deficit in Lei Nation. It seems that regardless of the investigation results from Yuan Chiye and Fu Xingzhou, the higher-ups have already set their plans in motion.
So, Chen Mobai surmises that major actions will likely take place within the Divine Wood Sect before Meng Hong retires.