Doom Patrol #11's release date has been updated to March 28, 2018 - four months beyond its originally-solicited Novmber 22, 2017 release date.
No reason was given by DC for the change, but the series (and this issue in particular) have been delayed on several previous occasions. The solicited Doom Patrol #12 was already cancelled, with the publisher stating it would re-solicit it "at a future date."
DC's planned Doom Patrol Vol. 2: Nada, which would collect issues #7 through #11, remains scheduled for release May 7.