Updated August 11, 2017: Following the unexplained order cancellation of Green Arrow Annual #1, series writer Benjamin Percy has explained DC's reasons - and it involves Christmas.
"Since it's a Christmas story, they decided it would be better as a seasonal release," Percy tweeted. "It's all finished -- they just want it out in Nov."
DC's November 2017 solicitations are anticipated to be released later this month.
Original Story: Green Arrow Annual #1, originally solicited for release on August 30, has now been "cancelled" at the distributor level according to a notice sent to retailers by DC Comics.
No reason for the cancellation was given, though the publisher said they plan to resolicit it at a later date.
Here's the original solicitation: