Well, "Time Out" magazine is not the first to list "The Devils" as a horror film. Back in 1990, writer John McCarty listed "The Devils," as a horror film along with Russell's "Gothic" and "Lair of the White Worm" as being three of the fifty best horror films made in the past three decades in McCarty's "The Modern Horror Film: from 'The Curse of Frankenstein' to 'The Lair of the White Worm.'" That's three for our Ken. The only director who got more mentions was Roman Polanski, who had four of his films listed.
McCarty's book was updated some eight years later by "Tell Me When to Look: Modern Horror Films from 'The Curse of Frankenstein' to Today." As I haven't seen that one, I don't know which films have been listed and/or delisted.
And being the lazy sod that I am, do you have a web address for that issue of "Time Out?"