No, that’s not possible unfortunately. The mailchimp addon only does what is explained on the addon’s page:
Your users can unsubscribe anytime. Also, if you have double opt-in (the default setup), then the user doesn’t get added until the confirm via the email.
You can use your terms and conditions to explain how things work on your site in a transparent manner. If you enable the terms and conditions feature, the users have to agree to it before they can do a checkout.