Event Management is intended to use a private sharing model for the Event and objects directly related to the event. Private sharing means the event and its related records are only available to the creator of those records. Anyone above the record creator in the role hierarchy also has visibility to the event.
Auto-sharing to team members provides edit permission to the event and its related records to anyone on an event team. More information can be found in the Record Sharing to Team Members topic.
The following objects use a private sharing model by default.
Additional sharing rules can be applied on top of the private sharing model to share events and related records with additional groups. If sharing to additional groups outside the event team, it is recommended to create base layouts by profile and configure when these layouts are used within the page layout engine.