There is newly disclosed resolved report Program Email Nofication settings ignored when being added as an external contributor, However i found that the fix is incomplete.
I have found that email invitation for a collaborator (bounty splitting) still disclosing the Report title in email when the notification comes from
Manage Collaborator invitation.
Assumes that Manage Collaborator (bounty splitting) is enabled to the program
Sensitive information disclosing bypassing the program settings.