Bald Cypress are known for providing lots of foliage to clean up every fall. Along with that will be some smaller twigs as you note. Branches can be brittle and break away in windy situations. While we are getting farther away from the 2012 drought, some impacts are still being seen and perhaps some the twig loss can be attributed to that as well. Squirrels and similar sized mammals will climb and in so doing can crack twigs which will die and come down later. Adult raccoons can also do substantial damage too.