[j. d. worthington]

I'd say that's not too far off the mark. I'd call it more of a marketing strategy than a genuine difference in genre. An awful lot of the classics of the horror field would, these days, be called "dark fantasy"... an enormous amount of Blackwood would come close to that classification (even though there's none of the reliance on what are now traditional fantasy tropes), because there's very little "scare factor", more an eeriness or nightmarish quality. The same would go for most of Machen, a fair amount of Dunsany, several tales by John Buchan....