According to Wrestling Observer Radio, Kalisto will be defending the United States Title at WrestleMania 32, but not against Alberto Del Rio. There was speculation Kalisto and Del Rio would continue their feud into ‘Mania, but that is not currently the plan anymore for some reason.
While not confirmed it’s possible Ryback could be an opponent for Kalisto. Ryback looks like he turned heel again and currently doesn’t have an opponent for Mania. But wow, what a mismatch that would be. Ryback could eat Kalisto for breakfast.