23andMe sent out the following message to all of their customers today.
We are sending you this email because you have historically used a username to sign into your 23andMe account. Beginning September 27th, 2017 you will need to sign in using the email address associated with your user name, as we will no longer support usernames as a means to sign into the site.
There are no further actions required of you at this time, but if you have questions or difficulties logging into your account, please contact Customer Care using our online form.
The 23andMe Team