jaredhanson/passport-google-oauth — pull request #8 by blaine (2013-01-21 21:43:39+00:00)
Title: This parameter allows providers who know the email address of the user to bypass the account chooser prompt screen

This is an essential parameter for efficient login flows for sites that don't want to rely on google to offer a choice of accounts to sign in with.

Added to OpenID Connect here, so should apply to the Microsoft OAuth 2 endpoint, too: https://bitbucket.org/openid/connect/commits/970a95b83add