With X18, you can now have schedule callouts automatically align with the orientation of the object label. This option is available on the Label panel of the Schedule Specification dialog.
To enable this behavior, turn on Automatic for the text angle, then enable both Auto Adjust Text Direction and Follow Label.
Please note that these options currently work only with certain callout shapes. If you find that the settings are grayed out, it is a known limitation. This issue has already been reported to our developers for review.