This is actually pretty old news. Since they were first spotted off of Grey's Reef in GA they have been seen from New Jersey to FL
They do have predators. Sharks can and will eat them, frogfish seem to have no problems eating them as well. Plus the myriad of fish that enjoy picking ie. big angels and queen triggers. I not believe they will have as massive an impact as people are fearing. They only eat smaller species of things and are relatively slow growing population-wise. There are so many invasive species as it is that one more really isnt that bad. Orbicular Batfish are found now in the Keys along with numerous others that shoudnt be here. Besides at the rate they eat and reproduce, the commercial fisheries will have long since wiped out the shrimp and minnow populations before lions play a major role.