We added review_every_post for sites where you need total control of what gets posted. You can’t afford to queue posts in this case without paralyzing all discussions, hence the need for a shadow reviewable. Since we don’t queue posts, posting rules apply. You shouldn’t be able to post 50 times in a row.
For scenarios when you need pre-approval on specific categories, or posts containing watched words, I think queueing is still the way to go.