Hmm, that's interesting. If I was writing a review moderation algorithm, it would leave only one copy up if there were multiple substantially identical reviews. Those are likely to be written by bots that mutate a common review and post, or even if some entity circulates a "review" to its crew of minions who write fake reviews based on that template.

I'd also write it to remove reviews written by a single account if the reviews across diverse products are substantially similar.