Are Drush vbo-execute actions supported?
After much searching to no avail, I decided to dig into the VBO codebase. It turns out that I was using the wrong action id (the 2nd argument to the drush command after the view id). Whatever action id was being used in the post I referenced is not the right one (either it was custom or VBO has since changed the convention for action id's). I discovered this by finding the file that implemented the action (delete) that I wanted, which happened to be in /drupal_root/modules/contrib/views_bulk_operations/src/Plugin/Action/EntityDeleteAction.php. This file has an annotation block that specifies the action id to use:
namespace Drupal\views_bulk_operations\Plugin\Action;

use Drupal\views_bulk_operations\Action\ViewsBulkOperationsActionBase;
use Drupal\Core\Entity\TranslatableInterface;
use Drupal\Core\Session\AccountInterface;

/**
 * Delete entity action with default confirmation form.
 *
 * @Action(
 *   id = &quot;views_bulk_operations_delete_entity&quot;,
 *   label = @Translation(&quot;Delete selected entities / translations&quot;),
 *   type = &quot;&quot;,
 *   confirm = TRUE,
 * )
 */
class EntityDeleteAction extends ViewsBulkOperationsActionBase {
...
}

running drush vbo-execute my_delete_view views_bulk_operations_delete_entity did the trick! No idea why there doesn't appear to be any documentation about this (at least that I can find), but I'm glad I finally figured it out and hopefully this helps someone else having the same trouble.