I guess you could write a script that will walk through all the accounts and restore any shares they've dismounted. But that seems like a waste in many ways. Note that ZCS 6 offers a couple features to simplify sharing.
First, you can see what a given user has shared with you simply by entering their address under Preferences>Sharing.
Second, you can see any shares that have been "published" to a distribution list that you belong to, in the same interface. About "publishing" a share, see
sharing with DL