Personally I wouldn't mind seeing Moana incorporated into what is already there. I know it's sacreligious to say, but I find this latest version to be really boring. It's one of the very few attractions we didn't hit during our recent ten day stay. I know it is a classic and still enjoyed by many, but you really can't blame Disney for finding this show to be underutilized.
My main concern here is similar to the Gran Fiesta Tour, where there is the possibility you could make a smaller attraction too popular. As much as my family likes Moana, I can't imagine waiting an hour for a five minute show.