Well, I don't know actually. It is more a reflection of part availability, options, and aftermarket support. I think the aftermarket sees the E-Savage as a short lived vehicle. I have not notices much interest in it and so I would be hesitant to purchase one if it seems likely to be discontinued. I had an HPI RS4 MT. It was a great truck, but it was discontinued, I could not find replacement parts for it and had to get rid of it.
As fas as the nitro Savage, it will not be discontinued anytime soon and there is a flood of parts support. But the E-savage does not share any parts with the nitro.