So? What does that reveal? It’s still matched by rank. And you’d know you’re matched by rank because your out of bonus stars. So if you’re out of the bonus at Plat 7 and you get matched against a Gold 3, you know it’s only because there wasn’t anyone available closer. That’s not giving you any new insight. We already know that’s how it works.
That’s irrelevant to the point. You claimed that hiding opponent rank was to avoid complaints on the forums. People at Legend can still see when they get matched with a non-Legend. Examples are all over youtube and twitch. How do you think people found out about the weird matchups in the first place? The complaints will still be there. (And again, a Legend not knowing his opponent’s rank does not deprive him of anything relevant to his gameplay.)