Today, Amazon Pinpoint added support for enhanced message templates. You can create templates for email messages, push notifications, and SMS messages for all of your Amazon Pinpoint projects. Message templates help you design, manage, and reuse your messaging content in an easy and effective manner.

from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/10/amazon-pinpoint-adds-support-for-message-templates/