Like many of our "fantasy" or "apocalyptic" pieces, the premises are based on real concerns. Japan and much of Europe are suffering from near-stagnant or even declining populations, and at least some of these countries also have really large elderly populations relative to the national whole. So, more concerns about flight to the cities, brain drain and intellectual property, and commitment of the young to support their elders.
Also related: the depletion of American Social Security and declining predicted standard of living for youth compared to prior generations.
Btw, re prior info: There have been a lot of previews and some interviews about it before on Sci-fi Channel. But not the entire film, as far as I know.