Hi Pedro,
Role Reaffirm option is similar to User Access Review where role approver need to reaffirm the roles based on the Role Reaffirm dates maintained in BRM for the roles.
In User Access Review (UAR), based on the roles assigned to the users in target systems, UAR requests can be generated and reviewers can be set as either MANAGERS or ROLE OWNERS.
Role owners can then review the UAR requests and can Approve/Remove the roles accordingly.
Since Role Reaffirm is not supporting Email notifications to the role owners, may be you can raise a OSS message to SAP and can discuss with them about your requirement.
Else if UAR suffice your requirement you can enable UAR in your environment.
Regards,
Madhu.