You have it backwards; the arranger will become a niche market because of the styles, many of which are song specific so requiring minimal input from the user, plus they do not cover anything like the younger generation want, which is loops and arps that can be put together in a flash (The arranger is so cumbersome in this task that it is hardly surprising that most youngsters aren’t interested) and give them a nice base to work on. (Until you get rid of canned (And antiquated) styles the arranger can only go downhill as those that do use them die out)
The video you linked to shows exactly why most youngsters are not interested, as they could put together something in the genre they want using their iPad in a fraction of the time.

Bill