Heat oil in a large saucepan over medium-high heat; cook and stir ground turkey in hot oil until turkey is browned and crumbly, 5 to 10 minutes. Drain excess fat. Stir chicken broth and taco seasoning mix into turkey; cook and stir until liquid reduces and thickens, 3 to 5 minutes.
Stir orzo into turkey mixture, bring to a simmer, and cook until slightly softened, about 2 minutes. Add salsa to turkey-orzo mixture, stir, and transfer mixture to a 2-quart casserole dish.
Stir muffin mix, creamed corn, and milk together in a bowl. Spread corn mixture over turkey mixture.
Bake in the preheated oven until a toothpick inserted into the center of the casserole comes out clean, 35 to 40 minutes. Spread Mexican cheese blend over the top of the casserole and bake until cheese melts, about 5 minutes.
