When you delete a member’s WordPress user account from your site, you might also want to unsubscribe them from your MailChimp audience.
This code recipe will automatically unsubscribe a user if their WordPress account is deleted by an admin.
The MailChimp Add On needs to be installed and activated for this code recipe to work.

The Code Recipe (PHP)
Adding the Recipe to Your Website
You can add this recipe to your site by creating a custom plugin or using the Code Snippets plugin available for free in the WordPress repository. Read this companion article for step-by-step directions on either method.