Coming off the success of 2017's Wonder Woman, WB suddenly found themselves with a lot of projects in development but not a whole lot of confirmed release dates on their slate. That was certainly understandable given the fact that the studio needed to circle the wagons a bit after 2016's PR nightmare of Suicide Squad and Batman v Superman: Dawn of Justice. But Wonder Woman has led to renewed optimism regarding the DCEU leading into November's release of Justice League.
Aquaman the only DCEU film releasing in 2018 and there's nothing on the slate for 2019 (The Rock's schedule is already jam-packed so we're doubtful Shazam will be released). Variety's report that WB wants Suicide Squad 2 to start filming in early-2018 makes perfect sense as they need to start confirming their plans for 2019.
Another recent report also states that WB wants Ben Affleck to go in front of the camera in 2018 for his standalone Batman pic. A Suicide Squad sequel and The Batman would certainly make for a strong year. There's also the possibility that WB moves the Justice League sequel back to its original June 2019 release date now that The Batman is delayed.