Shazam!, one of the 2019 entries in Warner Bros' DC Cinematic Universe slate, has had a tentative date of April 5, 2019 attached to it for a few months now. It seemed like an awfully long time away to have Dwayne Johnson tied up into something that won't see release for years.
While nothing has officially changed on that front, Johnson himself hinted to MTV that perhaps we may see Shazam! sooner than we think:
Well, you know, it may happen a little earlier than what has been predicted. The script is coming in, it’s great, the support from the studio has been great, and it’s just a great opportunity especially with Black Adam where you can take a guy who starts off as a bad guy, turns into an anti-hero, we can make him vicious, a little bit of winking charm.
Given that Superman v Batman: Dawn of Justice and Suicide Squad are both locked in, and Wonder Woman begins shooting this Fall, it's doubtful that Shazam! can get moved up too far ahead. This goes doubly so for 2017 with both Wonder Woman and Justice League Part 1 headed for release that year. I wouldn't be surprised to see Shazam! take over The Flash's spot in the 2018 schedule though. With not even a screenwriter announced for the latter as of yet, that might be the most likely development.