That does sound great. I can see it working well for things like the Jungle Cruise, the Land and AK Safari where a sign language interpreter wouldn't work at all and a script would not work either.
I hope that the quality is better than some of the TV shows I have seen. We had videotaped the show Survivor, but something had happened to the sound (it didn't record), so we thought, no problem, we'll just watch the closed captioning. It turned out to be such poor quality that it was almost incomprehensible. Words spelled so wrong that you couldn't tell what they were saying, things that the captioner figured out later were wrong, so it was inserted farther down. I feel really bad for anyone with a hearing disability that is relying on the information they are getting from closed captioning.
My DD likes the closed captioning on sometimes while she watches TV, so I have seen the variation in quality. Some is really good (even news shows where you know it is real time captioning). Some is really bad, including shows that are scripted so they should be able to get it right.