You can make this vegetarian and vegan. This is also gluten free?
Bacon is great crumbled on the top but you can totally leave it out. But, as a true Southern dish, would you really want to leave it out ;)
Use white rice, brown rice, or wild rice. Using brown or wild rice will increase the cooking time or you can par boil it ahead of time.
The bell peppers, Rotel, and Southwest seasoning gives it a Tex Mex flavor profile, but you can absolutely leave it out and just use plain diced tomatoes and a simple all purpose seasoning.
You can prepare the bacon and sausage ahead of time in a large skillet and store in the refrigerator until ready to make the casserole.
If you don't want to use pork sausage you can also use ground beef or ground turkey.