Why Mailchimp is no longer in the Shopify App Store

There are no immediate changes for merchants currently using Mailchimp, and we offer many other incredible email marketing apps. Over the past 18 months, Shopify has had growing concerns about Mailchimp’s app because of the poor merchant experience and their refusal to respect our Partner Program Agreement. Our terms require app partners to share all important data back to the merchant using Shopify’s API to help them run their businesses.

Source: community.shopify.com