Scorpio being a 4k only machine would be exquisitely dumb, so I'm basically assuming that people have their wires crossed and it's exactly like a Neo scenario where as long as the games run on the base console, they can upgrade the graphics and framerate on the Scorpio.
It's spaghetti right now, not just crossed wires. But I agree. Anything else would be too dumb to believe.
Likely the recommendations and specifications are based around a 4x resolution increase so that would make sense to make the Scorpio version 4K at whatever framerate and detail level the XB1 version is. Also the simplest option for the developer. But if the dev wants to do something else that's fine.
Framerate I'm not sure about. Unless they are including a significantly faster CPU, the framerate may be more likely to stay in line with XB1