This mostly depends on CB.
SocialLogin will create a user account with a username and email address communicated by the login provider service your using. That's all it does.
The rest of your question doesn't depend on Social Login at all. It's the same as asking whether CB would ask for additional information if you had created a user account in the Joomla backend and have the username and password to a user to log in. I can't answer that as I'm not the author of that software.
Nicholas K. Dionysopoulos
Lead Developer and Director
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