Not exactly. We’re not removing this, we’re just disabling it with ability to turn it on using the use_email_for_username_and_name_suggestions site setting.
Also, note that this change is done for DiscourseConnect, but not for other authentication methods (including authentication via Google). But the fix for other methods is coming soon.
Also, when generating username, full name have priority over email, authenticators try to use email for username suggestions only if the username and full-name fields in the payload are empty. This is something that can be customized with a plugin. But using email as the main source for username suggestions isn’t something that we want to do by default, especially for authentication via Google. The reason is that in this case, it’s possible to figure out emails of all users on the forum just by adding @gmail.com to usernames.