I’m seriously confused. The mountain used to house a dark ride, a flat, and a water ride. So, that space is not intrinsically intended for a coaster. Assuming the mountain isn’t raised, there is history to support pretty much kind of attraction that CF and KD believe would best serve the bottom line.
Honestly, the space isn’t really ideal for a coaster. I always felt as if I was in some abandoned construction dump site, when I was waiting to return to the space that passed for a station. Hanging out in the hot bowels of some defunct attraction with little to no airflow wasn’t a charming experience.
On another note, I think demolishing the mountain is a bigger deal than removing the coaster. The former is the iconic piece of history. The latter is just the most recent attraction housed there.
You are correct in that the mountain was created to house a flat/dark ride complex. The park was over-budget for this attraction when it opened in 1979. The original plans called for a second flat ride and another indoor scene for the Vouage to Atlantis water ride. The park dropped the 2nd flat ride ride and the final indoor scene for the water dark ride was added the following year when the ride was renamed to the Haunted River in 1980.