Just amateur speculation on my end, but I wouldn't be surprised if the is staying at 480' after all, with the 4-car R179s. But, wouldn't the only other places they could theoretically go be ENY or the , where the former already has an abundance of 4-car sets? Again, I could be wrong, but it seems that the Eastern Division will soon have more than enough cars on its hands--and it wouldn't be a shock for the to scrap their 600' plans without fair warning.
It will also be interesting to see the 5-car sets running.