I don't know if thats possible under the contract. Also I don't see Disney building an area around a character in which the character cannot appear.Black Panther might not be usable, but that doesn't mean that Wakanda and everyone else is off limits. I guarantee they could pull off a ride that featured T'Challa's little sister and it could be a blast.
I once suggested that Disney could add Nepal to DAK with an indoor dark ride/coaster that used The Ancient One and Wong from the Dr. Strange movie. It doesn't necessarily have to have the main character in the ride for it to be successful.
Dr. Strange can be used in WDW if they choose too.