>If you're clever you add a manual review stage in the pipeline and have the db engineers approve the generated migration script before deployment is completed automatically.

This is how I've set it up at my current employer. It works well. We modeled it after the Terraform Plan/Apply steps, and double check that the script generated by the "apply" step matches the script generated by the "plan" step, since these can occur at significant temporal distances, and fail it if not, just so that we can be sure what we've read and approved matches what gets executed.