Frozen in a Norwegian styled part of Fantasyland is fabulous.
Frozen in a Norway pavilion in a World Showcase is not.
But okay, that ship has sailed (Ha! Medium quality word play!) EPCOT is dead, in the IP Replacement Park anything goes.
A lot has to do with timing. The Fantasyland expansion was planned and green lit before Disney knew what a "Frozen" was. I think in hindsight - if the expansion would have happened a bit later Frozen could very well have been the center piece of that expansion.