For those that want to know: I used the tutorial in my post above to add a new column in the Dashboard. To display which type of post the user submitted, I added a “Hidden Field” to my forms and used these values:
Meta Key: type_of_post Meta Value: Review
Repeated the same for my other custom post types, changing only the Meta Value and leaving the key the same.
Use this to display the type of post in your dashboard: