As stated here: https://www.lawdonut.co.uk/business/marketing-and-selling/marketing-and-advertising/your-email-marketing-and-anti-spam-law
QUOTE: "Specific consent requires some positive action by the subscriber. If an individual omits to deselect an opt-in box you have pre-ticked on (eg an order or enquiry form), that is not a specific consent. If they specifically tick the opt-in box or you make it clear that by entering his email address in a field they are opting in, these are positive acts for this purpose."
It's not consent if a user fails to de-tick a preticked form.
Therefore we need the ability to set the MailChimp subscribe form to de-ticked as default.