It's true, they did - but Us has significantly more characters that translate to a haunt environment. While its themes are political, they also aren't nearly as brazen and openly provocative as what's in the new Candyman.
I'm not saying it can't be done, but I'm not peronally sure how they would execute it. I don't even know which "Candyman" they'd use. With that said... I'm sure if the producers are willing to go for it, Universal would love to use it. Marketing-wise, the hook is as popular as the "Us" scissors.