The universe has whatever nature it has, whether we like it or not. Even if it were knowable — which I (and perhaps Gödel) tend to doubt — that nature is really irrelevant.
Just as we should not build our homes on shifting sand, it seems similarly dangerous to shop for cosmological theories based upon how they stack up against our preferences about free will.
Render unto science that which belongs to science — a tremendous body of startling observations to account for, with the most useful observations difficult or impossible to make. The curve that “best fits” the existing data will continue to change radically. It’s a fascinating and worthwhile study — but we cannot allow our ethics to chase that constantly-moving goal-post.
Every day, trial after trial, our actions continue to have measurable consequences. Whether science supports the existence of free will or not, we should still proceed as if it does.
Were the future completely predestined, there would be no free will, but that destiny is still more palatable if people are obliged to either comply with a social contract or experience the consequences of violating it. The evolutionary advantage may only be apparent in retrospect — a majority of the present population lives under some social contract, because societies that were fated to establish such contracts then found themselves fated to thrive.
Free will also has little meaning at the other end of the spectrum, where every underlying event is “completely” random. Still, in the presence of a social contract, the law of large numbers creates better outcomes. Thousands of ‘random’ impulses to murder one’s neighbor are completely overwhelmed by millions of ‘random’ impulses to not do so, including as a last resort impulses to avoid the consequences of being convicted. Free will (with social consequences) is then a fiction with a definite evolutionary advantage.
I may never really know the universe intimately. Perhaps there are unlimited possibilities, but as conscious agents, in aggregate we determine the one and only universe that is actually realized for us.