Yes, it's a near-universal legal requirement that humans be able to tell if something is an ad or not. So once they sabotage that, they're in hot water.
Is there any enforcement of this? Like at all? All the review bots and bots promoting random crap on reddit say otherwise. Traditional media still pays lip-service to this, but only barely.
I was under the impression that America had very few legal restrictions on ads at all.