They didn't go down they got lost in transition. Paramount Kings Island was a Theme park with rides based on their movies being that it was a production company so themed rides were their forte. When Cedar Fair bought Ki by choice or not they didn't keep the licensing needed to keep the movie themed rides as they were. Cedar Fair is a Thrill park known for bigger, bolder, faster; breaking records with rides. Theming isn't their forte, beyond a color scheme and name, Mystic Timbers shows that theming is outside Cedar Fairs comfort zone. MT is still awesome of an attempt at theming but the"story" was kind lost on me.
So when they removed all the licensing the rides didn't make any coherent sense anymore.
CF should have just taken tomb raider out of its shell as the ride itself fit very well in cfs record breaking theme as it was the world's only giant top spin in existence. Had they just taken out the liscensed stuff and the building it would have stayed. But as the crypt it just no longer made sense and it lost its ridership and therefore no longer worth keeping.
Ki it's a unique child of the Cedar Fair family because it came themed and over the years it's starting to fit more in as a Thrill park and less of a theme park.
So I think the new giga will have a nice color scheme and name and maybe a slight story to fit in with the area but that's about it.