I was thinking both of Disney setting trends in a lot of different ways, from the very opening of Disneyland up to, admittedly, constructing structures like the Swan and Dolphin. I'm not an architectural or design historian, but my understanding was that Eisner's "starchitects" were brought in to do innovative, cutting-edge work, the kind of work that appeared in both industry journals and the mainstream press and was studied in higher education classes, all to enhance the reputation of the company and CEO. This is in sharp contrast to modern structures like the Riviera, which looks like a generic I-drive hotel and is unlikely to pop up in any doctoral programs.
This doesn't mean that WDW's best work "existed outside of contemporary fashion," which no piece of popular art or culture, no matter how bold or new, ever has; Disneyland was an evolution, albeit a brilliant one, of multiple pre-existing forms, most notably the amusement park. But at the same time Disneyland also worked to define something decidedly new, something modern Disney seems in no hurry to do.