Those photos are not really comparable since one shows the whole attraction and the other only shows what's above the construction wall. Apples to apples would be more like this, which is a much less extreme difference:
View attachment 763403
View attachment 763405
Second, and I think more pointedly, Splash Mountain used Forced Perspective far less than people seem to recall. The real trick with Forced Perspective is to take things of objective, knowable size and shrink them relative to the percievable size of the objects in front of them. All the objects on the Splash facade - rocks, grass, trees - come in variable sizes in nature and don't really "force" the perspective by getting smaller. For all we knew the rocks at the top of the ride were just . . . meant to be that size. Not that the effort was even made; in the above photo you can see the rocks towards the top of Chickapin Hill are
bigger than the rocks towards the bottom.
Meanwhile, the topography of the facade is actually the same as before, it's just that the clay is covered in moss and the rocks are covered in plants. All they did was chop off the stump, which
does make the facade shorter, but wasn't part of some carefully calibrated Forced Perspective. The thing looked big because it is big. It just had a pointy thing on top and now it doesn't. Hardly a masterclass in Forced Perspective.
Same with the drop, whose channels are perfectly parallel and have never made any effort to force the perspective of the height. The drop looks big because it is -
still is.