Tried to edit the list of sysadmins who received the email notifications for events such as Data Archive, etc. and found that all sysadmins received event notification emails.
Working as designed for all SysAdmins to recieve the notifications.
There is no solutions for this. All SysAdmins were opting out of receiving the emails and as many of them are important to the continuing function of the tenant it was changed so that all sysadmins receive emails.
If there is someone who does not wish to receive the emails they can be switched to an Admin user and assigned an Access Profile with permissions appropriate to their responsibilities.