I dont think building a coaster with 9+ inversions is unrealistic but I do think an inverted coaster that is nearly 250ft and 75+mph with 9 inversions is a bit unrealistic because it would be very intense, very very expensive and would take up a huge amount of space and would have a hell of a lot of trims.
They probally got carried away when they saw Alpenguist and said we will beat that with more height, speed and the inversion record but it never happened probally because of a lot of reasons like space, money etc... and they got a standart Vekoma SLC instead.