I still feel like this approach to arguments is an anti-pattern. Instead, I would recommend:

- `wp blog empty`: Empties the entire blog, including posts, comments, terms, users, options, etc.
- `wp blog empty --post_type=post`: Empties all of the Posts from the blog, including attached postmeta and comments. Leaves other data.
- `wp blog empty --post_type=page --taxonomy=page_category`: Empties all Pages from the blog, including attached postmeta and comments. Also deletes all of the 'page_category' terms. Leaves other data.

Largely, this is the better pattern to follow because it allows the operator to be more deliberate.