When Atlassian Accounts are Billing Admins for a subscription, their Atlassian Accounts can not be deleted, unless the products are deleted or their Billing Admin role is revoked. 

This also happens for Rovo. While Rovo doesn't have a self-service option to be deleted, it still blocks the deletion for accounts that are billing admins of an Organization that holds Rovo. 

It would be good if the deletion of Atlassian Accounts bypasses the Billing Admins for Rovo.