Releasing a new predator into an environment might disturb the food chain.
It might lead to a decrease in an animal. For example a mouse.
And the decrease of that mouse who eats plants would lead to an over growth of plants
On top of this, the swamps of Florida are not one of the anaconda's natural habitats where it can survive and thrive. A different environment means needing new adaptions for survival.
(also) - a domesticated pet is used to being hand fed where the animal does not have to find, hunt, and destroy its prey.
