Consider the following constellation:
User A creates a file and share it with User B, where User B has configured to get an email notification on each file event in his preferences. Now user B get an email notification about the shared file from User A.
But when the file got changed by User A, there are no notifications send to User B - even when User B is actively following the file.
This behavior is different in communitys: When we configure to get emails about every community event and someone changes a file, the other members got notified.
Please make this consistent so that changes on shared files also generates (mail) notifications - at least when an user is actively following that file.