Believe it or not, @Plucky, there are newscasters and other humans living and working in the deep south who are from other states and even other countries. If a newscaster in the deep south is from the deep south, unless they’ve worked to change their accent, I’m sure their accent would sound like they are from the deep south.
When you say “sound southern,” you should also know that involves too many dialects and accents to count. People in Maryland may sound southern. People in parts of Ohio sound southern. People in parts of Louisiana sound French. People in parts of the mountains where I’m from in Virginia have a Scotts-Irish dialect and roll to their accents.
Scranton, Pennsylvania, residents namely have a English and Irish influence in their dialects and accents. Other part of Pennsylvania where coal mining was a way of life is known for their German, Irish, Italian and Slavic combination on their accents and words. It is all interesting and beautiful when you think about how it.