Hi Andy,
I am facing the similar issue as Unable to fetch email address using rest Api if setting profiles email id 'Only you and admins' . I have created an external app using Oauth 2.0 (3LO) authentication. I am making api requests for issues, tasks, etc, but if a person has set email address privacy to only you and admin, details of participants like reporter, assignee, etc of each issue is returned without email address.
I need admin's oauth to be able to fetch email Address of all members when their email privacy is set to 'only you and admins'. I am not sure what all I need to do for this. Is raising ticket as mentioned in the guidlines article enough or do I also need to publish the app in marketplace, since it is mentioned in Distributing your OAuth 2.0 (3LO) apps article "Users trying to install an unapproved OAuth 2.0 integration are warned that the app has not yet been reviewed by Atlassian. To get your integration reviewed and approved, follow the steps on Listing a third party integration on the Atlassian Marketplace."
Also, guidlines article is mentioning an email API and I am not sure what it means.