Event notifications are designed in SwissMetrics to be sent when a Group Member has been invited to the event. Otherwise, the event will be visible in the Events calendar for all to view unless it's been permissioned for only invitees to see.

However, if a Group Administrator would like to have all members receive notifications of all events (and other content) created in the group they can enable to Group Setting of "Configure new content notifications for members" to allow all members to get notifications on all new content. (note: this will generate an email and portal notification each time a new piece of content - files, folders, notes, discussions, tasks and events - are created. 

Below is a view of where this option is: