The feature for user search on Whiteboard shows hidden users on Azure AD.
The sharing feature on whiteboard searches users by directory search on Azure AD.
This feature shows everything, including hidden users!
If It go on like this, we can not use it at enterprise or university!
The attributes to hide User from Global Address List on AzureAD/AD should be eflected in all Office 365 applications.
To be honest, User search is best managed by Exchange ABP.