Gravity Forms MailChimp Add-On v1.9 is now available via automatic update. This release updates MailChimp group handling and also makes improvements with how new subscribers are handled.
The MailChimp API currently overwrites current groups for a subscriber based on what is passed to the API. Rather than append the groups, it overwrites them. We have updated the MailChimp Add-On so that it first gets the existing groups for that user and then appends their selections so existing group selections will still be intact. We have also added a new hook, gform_mailchimp_keep_existing_groups, to allow developers to change this behavior back to the overwrite behavior if they would like to do so.
We have also updated how new subscribers are added to a list if they already exist as an unsubscribed user or their subscription is pending and they did not respond to the MailChimp confirmation email. When this occurs, users will now be added as if they were a new subscriber. Previously subscribers were not added if they were unsubscribed or pending due to default MailChimp API behavior.