MailChimp wants to embed GDPR-compliance language akin to the following: "You acknowledge that the information you provide will be transferred to MailChimp for processing in accordance with their Privacy Policy (https://mailchimp.com/legal/privacy/) and Terms (https://mailchimp.com/legal/terms/).”

But, MailChimp allows open-tracking to be disabled. So, that wouldn’t seem to be a required element of their processing. Which means it’s for the controller to decide. I don’t understand how article 7 of the GDPR allows for email tracking to be immune from explicit consent.