Interesting, had no idea a cable driven system like this was installed in the US.
The WEDWay People Mover which is in TomorrowLand at the Magic Kingdom actually has a pretty surprising thruput of around 3800 guests per hour.l, and this was based on technology from the late 1960s and features an open air design. Modern advancements could certainly safely increase the top speed above its current 6 mph, especially on straightaway sections.
It would only go up in capacity, and modern advancements such as selectable destinations could most certainly be applied, meaning to transfers or additional lines.
Not sure of why Disney did not investigate this more given it could open potential revenue streams as it would be a solid technology to showcase. I could easily see hotel/convention center combos being interested in such a technology.