If we update a CloudFormation Stack outside of CloudFormation the template would be out of sync and there is no good way to 'refresh' the template - that was the wisdom based on old discussion a couple of years ago.
I do not see anything in the AWS documentation. Has this changed/improved something similar to Terraform Refresh
Unless I am misunderstanding... Even though terraform refresh would update the state file it would not update your *.tf files which would still be out of date. (Which would break the concept of IAC).
On AWS you can use AWS Config to see any changes that have happened to your infrastructure after your initial deployment to reconcile the differences.
You can also use cloudformer to get a current cloudformation template of your infrastructure. CloudFormer
