This is my last resort, as I have not found any information about this anywhere. I want to make users in Teams unable to search and see the names in their address book, I only want them to be able to see who is on their Team.
Use case: the users have various mental illnesses, and their IT-administrator sees it as confidential information if they get the full names of other members.
If you can't block the address book, is it possible to make aliases for the users?
How are the users invited? If they are invited as guests and not provided licenses as tenant users, then you can only see people in your Team that you are invited to. If these users are full licensed users you cannot block this as they have access to this same address list through other means such as OWA/Outlook address book etc. anyway.