It's a misnomer, but I don't think OP invented that language, it's the word Helm uses for that flag: https://helm.sh/docs/helm/helm_install/#:~:text=the%20instal...

I believe(!) that the "rollback" that helm attempts to put back all the mutated objects, which it can - in theory - do because it maintains the previous state in the Secret objects that contain the rendered(?) and the values for the prior revision

  try:
    for obj in manifest_objects:
      kubectl_apply(obj)
    revisions.push(manifest_objects)
  except:
    old_revision = revisions.pop()
    for obj in old_revision:
      kubectl_apply(obj)

type deal