> Are there any sources (besides this rather fantastical article) that BGI-Shenzhen is conducting large-scale research into the genetics behind human intelligence

Yes, that is well known, e.g., http://www.nature.com/news/chinese-project-probes-the-geneti... (depending on how you define large-scale -- see the piece).

> if so that research is going towards some sort of comprehensive national eugenics policy?

Now that, as far as I know, is mere speculation, albeit speculation that has been bandied about by many more individuals than just the author of this piece.