Jurassic Park, surprisingly, is like this as well. You can really tell as they enter the rotunda for the first time. We used the Widescreen for a long time for a reconstruction we're doing, but then saw that the full screen showed more of the ceiling and of the dome and windows, which were in question at the time, and so we used that.

HOWEVER, sequences that used CG didn't have that extra. To save on time and space, they simply imported the widescreen image into the computer for the CG sequences... so sequences with animals in them, you get a cropped wide screen. Images without animals, you would get more of the top and bottom of the image.

Which, I'd imagine, is probably the case with some of the other movies mentioned as well.