I used the term "prophetic" loosely - just where you project a fantasy as the background for a story and it turns out to be closer to reality at a later date than you imagined.
I think a novel based on how an independent Scotland might pan out is a very interesting idea - whether it is presented as fantasy, utopia, dystopia or has a consciously political stance. Or where the setting is simply a background for the real story (romance or, I guess, mystery, in your case).
Still time for yours to turn out to be "prophetic"!
My stories are not written from a political standpoint, more from a what can destabilise society and push things over into an "apocalypse" scenario.
This does make Brexit a very interesting concept, simply because it is about change, division, disruption and possible controversial outcomes.
But probably more fun as a subject matter for a story than as a political reality!
Writers can be quite heartless in their ponderings.