Let's see what canon says:
ALttP Talking Tree:
That man wished to create this world... this world is a world that reflected that man's heart.
ALttP Triforce:
The stronger that person's wish is, the more the Triforce will demonstrate that power.
Ganon's wish was to claim the world. That evil wish changed the sacred land into the World of Darkness.
Once he had stored up power there, Ganon intended come out into the World of Light in order to fulfill his wish.
Rauru:
The Temple of Light, situated in the very center of the Sacred Real, is the last stronghold against Ganondorf's evil forces.
Sheik:
The resting place of the sacred triangle, the Sacred Realm, is a mirror that reflects what is in the heart...
the heart of one who enters it...
Neither OoT nor ALttP say that the Sacred Realm is similar to Hyrule. They say the opposite:
-The Sacred Realm has a changing aspect, because it's a mirror that reflects the person's heart. Therefore, it doesn't have to be like Hyrule.
-The Temple of Light is on the very centre of teh Sacred Realm. Last I checked, the Temple of Tiem, which is supposed to be its counterpart in Hyrule, isn't in teh very centre of Hyrule. The geography must eb very different.
-Ganon wished to rule Hyrule. But his wish wasn't strong enough, so the Dark World was created. The implication is clear: Ganon's wish to govern Hyrule made teh Sacred Realm look like Hyrule.
Yes, it's canon.