Facebook / Google OAuth Service register/login


I am using the Facebook and Google oAuth providers to create users and log them in.

It seems that the endpoint always returns full user (name, mail, sesstion, oauth token) information after a successfull handling of the oauth flow (no matter of shadow user was created or just logged in with an existing shadow user).

Is there a way to check if the shadow user was already on posting to this endpoint?
So if the user logs out from my app, session get’s destroyed and user needs to do the oauth login again. But the shadow user is already created so the app should not display things like app onboarding screen etc).

Does anybody has experience in this case?