So you're telling me that the plugin automatically will pull the data for those that have abandoned carts for the newsletter recipients and I don't have to do anything else?
Just check "Use MailChimp for E-Commerce" setting on plugin configuration page. After that plugin will be send store data to your MailChimp account, including the necessary for the abandoned carts workflow. Then you can use this data with any MailChimp e-commerce features.
It might be worth updating the description of the plugin to include information like that.