Google Cloud Identity platform untrusted providers

Looking at this document (cloud.google.com/identity-platform/docs/concepts-manage-users) that talks about email verification which is necessary for Google Cloud identity platforms automatic account linking and de-duplication features.

Under the heading “Untrusted providers” Both Google and GitHub are listed.

How is it possible for someone to have a Google and/or GitHub account without a verifying their email? I have explored various different ways to create a Google accounts and/or to modify the email address of my Google account but I have not been able to change my email address without confirming ownership of the email address.