Everyone tries to compare to Photopost.
As far as my recollection Reviewpost has always had comments go straight to moderation. Been this way as long as I have owned it. There is no global moderation setting other than to display unapproved reviews.
Looking at the base code I would have to say Reviewpost is deliberately coded to set reviews to go to moderation. There is a global switch to exclude admin from this but user reviews all go to moderation by default.