apps that require email address for core functionality will need to submit their use case and be approved to use a new API for exposing email address. The new email API will be available on March 15, 2019.
Is there any more information on what this approval process will entail/what are approved use cases? We develop a mail handler app for Jira cloud which of course requires access to the email addresses of Jira users to send them email. Losing any access to email addresses would make our app non-viable.