Thanks to @womeninthecity for sharing this email for mailchimp that provides some clarity - anyone else receive it?
Last week, we sent you an email announcing that MailChimp is adding single opt-in as an option and making it the default setting in new and existing lists.
However, because your primary contact address is in the EU, your existing forms will remain double opt-in. You can change your lists to single opt-in on the Signup Preferences page at any time. After November 3, you'll also be able to make that change in each list's settings.
We made this decision after receiving a lot of feedback from EU customers who told us that single opt-in does not align with their business needs in light of the upcoming GDPR and other local requirements. We heard you, and we’re sorry that we caused confusion.
Please know that we’re committed to helping our customers get ready for the GDPR. Double opt-in provides additional proof of consent, and we suggest you continue using double opt-in if your business will be subject to the GDPR.
For more information on why MailChimp is making changes to our opt-in choices, read our blog post.
Please reply to this email if you have any questions.