Was that always true? I had a call from Yelp at work where one of the selling points was controlling your profile, in which they mentioned "removing spam" and "offensive reviews" (they might have said "fake"). I took that euphemistically when combined with rumours I'd heard. But that was some years ago (maybe 5+, in UK); and could have been overselling or phishing by a third party I suppose.
How do you handle offensive reviews (like swearing, libel, personal details), do Yelp really manually intervene?
Don't they remove fake reviews, in which case a business can say the review is fake.
But perhaps they do the other thing that you suggest too.