I found your comments quite thought-provoking, and thank you for sharing. If I may, I'd like to add a few here of my own.
Perhaps from a marketing viewpoint of the over-50 demographic, your comments may be accurate; maybe Disney might not consider this group to be the target audience for their future attractions’ budget. And, although I agree that some similarities and preferences may be found in any specific demographic sample, I also believe that people’s interests can vary widely, regardless of their age group.
Moreover, if Disney’s current assumption is (if this is a fact) that the younger demographic is only interested in thrill rides, and not at all in an innovative, fun, and educational park (preferably, more along the lines of Epcot’s original FW & WS concept), then I think they're doing a disservice to this younger group of guests. Why? Because, a "one size fits all" predetermination, doesn't even give these newer visitors a chance to experience a completely different type of attraction for themselves, anymore.