The train is bookable to ATL tomorrow, so it is running as far as Atlanta. Today's 19 is currently approaching WAS.No reason why WAS to ATL (or BHM) can't be run. Amtrak does ATL when NS does track work south towards NOL and if they can't manage to handle trains in their home city of WAS, they need more help than even Biden can give them.
You're correct, there isn't any reason it can't be run as far as Atlanta, especially since they're running it.