It's doable and wouldn't be terribly difficult either. The trick seems to be to expand the train track rather than remove it.
View attachment 183629
Red is existing.
Blue would be the expanded route.
green would be the relocated train station
orange would be bridges going over the tracks. The existing grading of the park is pretty well setup for bridges in that area already so it wouldn't take much.
This would give open access to an area roughly equivalent to the size of safari.. That said this is already disney's largest park and pretty much everyone is in agreement that Dinoland USA is next on the BIG remodel list and there's a few acres behind primeval whirl they could plop a ride building on if desired.