By default, the Active Directory account status of device is maintained when the object is created in the target. If a device was Active Directory enabled in the source, it will be enabled in the target, and vice-versa. Or, choose enabled, to make all migrated devices immediately Active Directory enabled, no matter what their status was in the source.
Maybe you want to ensure that these devices should not be available until a later time even after the device has been cutover. In that case, you can choose disabled, which will cause all migrated devices to be Active Directory disabled, no matter what the status in the source.