For the price it'd cost you to buy this card, you can get a real D50 used (in good shape) on Ebay.
I don't see this happening. Not saying it won't, but I don't see it. Just like I don't think we'll ever see an SRX-based ARX card. I have a funny feeling that Roland will continue to move forward with new technology (ARX and beyond) than continue to make new technology (ARX) just to keep old technology alive (D50, SRX, etc.)
We'll probably see classic D50 presets in our Roland keyboards forever, though.