On lines 81 and 86 of JPATH_SITE.'components/com_users/controllers/registration.php', after admin verification success and activation success (respectively), the component should set the redirect to the login view, not the registration view. The user has already completed the registration form, and the next available step would be to login, NOT to fill out the registration form.
At least that is how I feel. What do you think? If we can come to a conclusion, I'll create a pull request that addresses the issue.