Of course things can change. There might be a rush back to the rust belt for some reason.
Or, more likely, the Sunbelt boom ends. Isn't Georgia's growth in particular is driven largely by the explosion of the Atlanta metro area? And a large portion of that growth is coming from a particular subsection of the US population (African Americans)? And, IIRC, the Atlanta area is already experiencing water issues. I'm not sure how much more it can keep growing, and if rural Georgia keeps declining like it has been...
On the other hand, I could very easily see Georgia passing Ohio within a couple decades, but there are so many variables at play here.
The water issues of Atlanta are wildly overstated, largely due to the fact that the region was experiencing a record-breaking drought in the early oughts.