Yes, that's what I understand, too -- at least in the early and moderate stages. A low protein diet may not be needed until the late stages.
Glad he's eating. Are you giving him any treats besides the canned food? Did you see the info. in the articles about being able to reduce phosphorus levels by adding calcium and foods high in potassium to the diet?
I forgot that one of the things Scout absolutely loved was a white egg omelet (yolks have phosphorus) with just a little cream cheese for flavor.