You can now use macros and transforms in CloudFormation templates to create AWS CloudFormation StackSets

AWS CloudFormation StackSets extend the functionality of stacks by enabling you to create, update, or delete stacks across multiple AWS accounts and Regions with a single operation. We are now announcing the support for CloudFormation Macros and transforms in templates that are used to create a stack set. AWS CloudFormation macros perform custom processing on CloudFormation templates from simple actions such as find-and-replace, to helping CloudFormation Macros use the same technology that powers transform the entire template.AWS::Include and AWS::Serverless transforms. CloudFormation transforms help simplify template authoring by condensing the expression of AWS infrastructure as code and enabling reuse of template components.

Source:: Amazon AWS