When going through social logins I have noticed that Yahoo always requires that the user agree to the Additional Terms and I was wondering why this is.
I did a quick test that used Yahoo for social authentication, but not directly using the Auth0 Yahoo connection and experienced the same behavior. This seems to indicate that it’s a decision from the Yahoo side and independent of the Auth0 Yahoo connection.
There may be some configuration switch when registering the application with Yahoo or parameter value that could be used to influence this, but if there is I could not find it. I would suggest you to inquire about this directly with Yahoo developer support.