Woah. As someone who read the first Hunger Games book soon after it was published, and quickly devoured the second and third books as they came out, I was a bit shocked to hear Suzanne read her own work!
Why? Because I didn't even think about the fact that Katniss would have a particular accent. As someone who speaks with a relatively standard American accents, that's the voice I read in. I know that many readers of the series probably read Katniss as Jennifer Lawrence, as they're familiar with the movies more than the original series.
I read the comments on this video on Youtube and, boy, were people MAD that she read Katniss that way! But here's the thing: wouldn't the author of the book herself know what she sounds like?! Even if the accent isn't a perfect Appalachian accent, it's been known all along that the districts were meant to represent a sort of future America, based loosely off particular areas, with district 12 being similar to Appalachian regions.
While I'm glad the accents were carried to the movie, I think that the book can exist as it was, and Suzanne would know better than anyone what Katniss sounds like!!