I'm going to have to guess that they have other plans for the material in this planned omnibus. Something that would tie in further with the Birds Of Prey And The Fantabulous Emancipation Of One Harley Quinn movie coming to a cinema near you in 2020. But for now, DC Comics has let retailers know that they are cancelling the Harley Quinn And The Gotham City Sirens Omnibus New Edition which would have collected Gotham City Sirens #1-26 and Catwoman #83 in February, with no plans to resolicit it.
They only published the old edition in April 2018, maybe they found a few more copies in a warehouse? It does still seem to be in stock at Amazon…
HARLEY QUINN & THE GOTHAM CITY SIRENS OMNI HC NEW ED
(W) Paul Dini, Peter Calloway, Antony Bedard, Verane Otero (A) Andres Guinaldo, Others (A/CA) Guillem March
Catwoman, Poison Ivy and Harley Quinn are tired of playing by other peoples' rules regardless of which side of the law they're on. These tough ladies have a new agenda that's all their own, and they'll use any means necessary to pursue it. But can they get along and work as a team? And who will get hurt along the way? Collects GOTHAM CITY SIRENS #1-26 and CATWOMAN #83.In Shops: Feb 05, 2020
But there are some books from DC Comics that are getting additional printings to keep them in stock.
- AMERICAN VAMPIRE VOL. 1 TP 7th printing
- AQUAMAN BY GEOFF JOHNS OMNIBUS HC 3rd printing
- BATMAN: DARK KNIGHT III: THE MASTER RACE TP 2nd printing
- BATMAN: UNDER THE RED HOOD TP 8th printing
- BATMAN: YEAR ONE DELUXE TP 13th printing
- BEFORE WATCHMEN OMNIBUS HC 2nd printing
- GREEN LANTERN BY GEOFF JOHNS OMNIBUS VOL. 1 HC 4th printing
- THE SANDMAN OMNIBUS VOL. 2 HC 4th printing
- THE SANDMAN OMNIBUS VOL. 3 HC 2nd printing
- WATCHMEN TP NEW EDITION 4th printing