From a Wall Street service:
We spoke with CSX, and the change back to a switching yard will increase capacity from 1,000 to 1,500 cars per day. More importantly, this will reduce traffic through other yards such as Waycross, GA and Cincinnati. As a result, CSX estimates this change can eliminate about 30M unnecessary car miles per year. CSX also expects this will help reduce some capital costs at other yards and the start-up costs to switch back to a hump yard should be minimal. So this seems like the continued evolution and implementation of precision railroading.
Fleshes out the corporate-speak.