Some cool new facts I've found over the past couple years.
The Simpsons Ride's storyline was originally going to revolve around the Springfield Nuclear Power Plant, with Mr. Burns serving as the main antagonist. But when Burns' voice actor (Harry Shearer) declined to participate, the Krustyland storyline we now have was developed in its place. There were also rumors of a Treehouse of Horror overlay for Halloween Horror Nights
Batman the Ride in Six Flags Great America was originally going to be named Hurricane (as both a homage to Tidal Wave and to tie it into the Yankee Harbor section of the park). But during the planning, Time Warner acquired 50% of Six Flags and the new owners made it a priority to promote their brands in the parks. Thus, Hurricane was renamed and rethemed to the Batman movie franchise.
Superstar Limo was almost retooled as Goofy's Superstar Limo. The main reason for the renovation being that Disney wanted to reuse all the fiberglass character statues that were being removed from The Disney Stores that were being rebuilt across the country and place them throughout the ride.
The Batman Stunt Shows in Magic Mountain were the only ones to not be staged in a specially built venue. The original show was held at the park's repurposed ski show venue. From 1995 until the venue's demolition in 2016, they were held in the repurposed dolphin show arena.
All of the original Marriott era buildings at Six Flags Great America are built to the same earthquake code in California, even though they didn't have to be. This is because Marriott intended for all Great America parks to use the exact same plans. It also applied to the aborted third park that was planned for the Virginia/Washington DC area.
Prior to INTAMIN introducing them in the early 1980s, Arrow had developed proof of concepts for a river rapids ride and swinging ship. But their parent company at the time, Rio Grande Industries, refused to let them develop them any further.