Re: Does anyone here know anything about sod?
I'm guessing that area must be very low if they intend on leave the old sod. But in answer to your question, no, you don't need to remove the old sod. It's dead and it will decompose, adding organic matter to the soil.
Just make sure they grade it right this time. When I was landscaping, I would have been embarrassed had I installed turf and left a big old low spot that collected so much water that it killed the turf. And I would have fixed it at no cost to the owner.
Next Reds manager, second shooter. --Confirmed on Redszone.