Add the chicken, black beans, corn, fire-roasted tomatoes, Rotel, onion, garlic, chicken broth, chili powder, cumin, smoked paprika, oregano, salt and pepper to a 6-quart slow cooker. Stir around the chicken to combine.
Cover and cook on HIGH for 3½ to 4 hours or on LOW for 5 to 6 hours, until the chicken reaches 165°F and shreds easily.
Transfer the chicken to a plate or cutting board. Shred it with two forks, then return it to the slow cooker.
Add the softened cream cheese to a small bowl. Ladle about ½ cup of hot broth from the slow cooker into the bowl and whisk until mostly smooth. Stir the cream cheese mixture into the soup.
Cover and cook for 20 to 30 additional minutes, or until the soup is creamy and heated through.
Stir in the lime juice and cilantro, if using. Taste and adjust the seasoning.
Divide among bowls and serve with crispy tortilla strips and desired toppings.