Will Scorpio be able to run Fallout 4 at max settings, 4k 60fps?
By "MAX SETTINGS", I assume you mean today's max PC settings.
The quick answer is that if a relatively straightforward Scorpio support patch were to be built, NO, a Scorpio version would not likely be native/true 4K/60fps with max PC settings.
What you could expect from a Scorpio version is:
Roughly 4x the resultion of the Xbox One counterpart, the same target frame rate (likely with a more consistent rate), with improved texture quality, and other possible minor upgrades in rendering effects quality.
Fallout 4's target frame rate is 30fps on consoles, so you shouldn't expect 60fps on Scorpio. F4's native resolution on X1 is 1080p, so an immediate 4x the res on Scorpio would be easily achievable, and you'd get true/native 4K. Since DF says the texture resolution on consoles seems to be the same as PC at max settings, you wouldn't see any magical improvements in textures, but that wouldn't be because Scorpio isn't capable of improving the textures, it's because higher resolution textures may not exist, and it would take time (read: money) to re-author assets for Scorpio that would surpass EXISTING "max setting" PC textures.
With not a lot of effort, Scorpio could probably do 4K, 30fps, with max or closer-to-max-of-PC-than-PS4 graphical settings... but I think it would be a huge stretch to think it could get anywhere near 4K/60 w/PC MAX. That would require closer to 8x the X1's perf, and Scorpio is closer to 4.5x of the X1. None of this is strictly linear, but it gives you the ballpark.
EDIT: If they wanted 60fps, they could probably do FAUXK (checkerboard), and run at twice the frame rate... but they might have CPU limitations which keep them from hitting 60fps, which would need to be factored into the equation... and this goes back to good ol' prioritizations, design targets, and decisions, decisions, decisions...