You bite your blasphemous tongue! The Bates Motel/Psycho house have been relocated twice on the backlot, pretty sure that they'd relocate them a 3rd time rather than demolishing.
And honestly, you forget one key thing about Falls Lake... they still use it for filming. Its not going anywhere anytime soon unless they decide to use it for another new attraction for the Studio Tour.
Also, they just built Supercharged, they're not going to wipe out those 4 areas of the backlot just to build DA after having just spent a crap ton of money for a crappy new studio tour attraction.