Messages can't be sent without approvals from many areas (Legal, Marketing, Business Area). Approval Groups are not an approval workflow where you can create rules for specific business needs considering other areas and send alerts when each part is required to validate a communication. Approval Workflows need to have an user interface where it's possible to create business rules for each category of messages (IBM WCA needs to support categories of message) considering all channels (Email, SMS, Push and Landing Page) not only Email.