I mean, if the game isn't coming until a year from now, that's still a lot of time for polish. I know game development and product design aren't entirely the same thing, but when I'm designing new features at work, the vast majority of what I show is wireframes and medium-fidelity prototypes. At best, I might do a couple of key screens in high-fidelity comps if I need something for an executive review.
That's how I've been looking at the little bit of footage they've shown so far–medium fidelity footage to show progress. I actually like that they're showing work in progress, though admittedly they could be a little more clear that it's actually work in progress footage. I'd much rather see this, than something that looks good now, but won't be representative of the final product.