* A new flag `-auto-approve` has been added to `terraform apply`. This flag controls whether an interactive approval is applied before making the changes in the plan. For now this flag defaults to `true` to preserve previous behavior, but this will become the new default in a future version. We suggest that anyone running `terraform apply` in wrapper scripts or automation refer to the upgrade guide to learn how to prepare such wrapper scripts for the later breaking change.
* The `validate` command now checks that all variables are specified by default.
The validation will fail by default if that's not the case. [GH-13872]