Combine the shiitake mushrooms and water in a bowl, assuring the mushrooms are covered with water; allow to soak until the mushrooms have softened, about 30 minutes. Drain and reserve the liquid for later use.
Preheat an oven to 375 degrees F (190 degrees C).
Toss the butternut squash, olive oil, and maple syrup together in a bowl until the squash is evenly coated. Spread onto a baking sheet.
Roast the squash in the preheated oven until tender yet retains its shape, about 30 minutes; set aside.
Bring the vegetable stock and the reserved liquid from the mushrooms to a simmer in a saucepan over medium heat.
Melt the butter in a large skillet over medium heat; when the butter begins to foam, stir the onion into the butter and cook until the onions are soft and golden, 5 to 7 minutes. Stir the wild rice and the Arborio rice through the onions until evenly mixed and coated. Add the white wine and mushrooms to the onion; cook, stirring occasionally, until the liquid has been absorbed, 7 to 10 minutes.
Pour enough of the simmering stock mixture into the skillet to cover the rice; cook and stir until the liquid is nearly completely absorbed. Continue adding stock about 3/4 cups at a time, allowing each batch to absorb into the mixture before adding the next. Cook and stir until the rice is tender, about 35 minutes total. Add the butternut squash; cook until the squash is hot, 2 to 3 minutes. Reduce heat to low. Quickly stir the Gorgonzola cheese and parsley into the mixture until the risotto is moist and creamy; remove from heat. Season with salt and pepper; serve immediately.