When changing a tag after the workspace has been initialized, executing terraform plan or terraform apply would show the error: Terraform Cloud initialization required, please run "terraform init" Reason: Backend configuration changed from "cloud" to terraform cloud. The "Reason" is incorrect. In this case, the "Reason" should read: "Terraform Cloud configuration block changed".
I have adjusted the logic around this switch case statement that was assigning the incorrect value to "Reason" (initReason variable) and also worded things a little different.