The new untitled dc movies is in addition to the Flash and Aquaman in 2018 and Shazam and Justice League part 2 in 2019. So three in 2018 and three in 2019.
Collider is reporting that this is misinterpreting the actual press release as The Flash and Aquaman though slated years ago for those dates were never officially scheduled for those dates.
However, they are the only ones reporting such. I can't find the actual press release to see who is right and who is wrong. If I had to bet, I would bet the 2019 is Batman. 2018 who knows.