The Ou Family runs a family business, similar to the Zhou Corporation, where the main power is held within their own people. Even if there are company veterans, they hold only a small portion of shares, and the family itself has the right of first refusal.
Therefore, Zhou Jianmin and Liu Jinhua's loss of their shares doesn't affect their ability to live in peace, eating and sleeping without worry, thanks to such agreements; even with unregistered shares, any transfer or sale must receive the Zhou Family's approval.
Unless they offload them on the black market at a low price, but if the buyer wants to make a profit, they still have to go through the Zhou Family.
By that time, the Zhou Family wouldn't be able to do anything about it.
Because it's difficult to assign blame for the loss of unregistered shares, and Zhou Gudao has been dead for many years now, if people insist that the shares were given by Zhou Gudao, the Zhou Family can only accept it.
