Missing the roux and the cajun trinity, I'm not really sure how this is supposed to be tasty. I've made a healthy gumbo for years and this does not come even close. Why eliminate the bell pepper and celery? They're the heart of gumbo flavor.
Brown the flour in the oven for the roux, you'll get maximum flavor with no fat.
Skip the cardboard turkey sausages and add a little lean bacon instead for the smokey taste, and chicken breasts for the meat. Much healthier and tastier.
Add some thyme to the cajun seasoning, and diced green bell pepper and celery to the onion and voila, you get real healthy gumbo!