Not a chance with
DCL. The dropped Aladin about a month before one of our Fantasy trips. The first week it was gone they replaced it with a really good guest singer, but they just let the theater sit dark that night on our cruise. I emailed them ahead of time about my disappointment, since it was really the only good show on the Fantasy (I think the others are pretty bad, actually) and we had first time cruisers with us. Disney was completely unsympathetic to my concern. I'm not sure any line would do anything, or even what I expected them to do, but it was a huge letdown at the time, since it's one of the reasons you pay a premium to Disney.
In short, as much as I like DCL, Disney rarely cares if you don't feel like you got what you signed up for. I get missing ports, it's part if cruising, but if you sell me a cruise that includes a headline "Broadway style show" as part of the package, you should do something if it is canceled weeks in advance (not due to some emergency situation last minute) and you fail to even try to offer a replacement entertainer. A little on board credit would have gone a long way.
At least on the Wish, they have some other shows that look great. The Fantasy's lineup on the other nights are it's biggest weakness, but I love the ship otherwise.