Major Disney rides that actually fit entirely within their on-stage buildings is really the exception, not the rule. See The Haunted Mansion, Splash Mountain, Indiana Jones Adventure/Dinisaur, POtC, etc., The difference here is that EPCOT has always been built with vast, wide open vistas. It’s much easier to hide a large building if you have complete control over the field of vision of a guest and a limited number of approach points and viewing angles. This is usually done by compressing views with other, smaller buildings and landscaping that are much closer to the viewer than the thing you want to hide.
It’s really always been a problem at Epcot. The Swan and Dolphin and Soarin’ were never great from a sight line perspective. And now we have GotG:CR to further lower the bar and establish precedent.