Earlier reports suggested that Warner Bros. was shelving Superman plans in their DC movie universe, which led to Henry Cavill (possibly) vacating the role of Superman he's played in Man of Steel, Batman vs. Superman: Dawn of Justice, and Justice League. In its place, WB was moving to a Supergirl movie, and a new report says that the film is slated to start production in the first quarter of 2020 (via Forbes). The report also suggests that we should start hearing casting information in the next few months.
If that's the case then it appears Cavill's time as Superman may be coming to an end, or if not then his Man of Steel will be put on the backburner for a bit. After the success of Wonder Woman, WB released their epic team-up film Justice League, but unfortunately, the colliding visions and Frankenstein cut of the movie didn't resonate with fans of Zack Snyder or Joss Whedon.
That's a big part of the reason fans continue to voice their support for a fully released Snyder Cut of the film, but it is also the reason why after the billion-dollar success of Aquaman WB has pivoted and put less emphasis on their connected universe. They've started to put more focus on character-focused stories that aim to bring that particular hero to life, with the lightest of tethers in place regarding the greater universe. Shazam! followed this mantra and was another feather in DC's hat, though it wasn't as successful as Aquaman. Regardless, it received a positive response, and it is likely going to be the path for future DC film for a while.
Next up is the Todd Phillips Joaquin Phoenix Joker movie, and then Wonder Woman 1984 is up to bat. After that, we're sure an Aquaman 2 is somewhere in the cards, and of course, now there's the Robert Pattinson starring The Batman movie from Matt Reeves, which again isn't connecting to any of the previous Ben Affleck Batman material.
Supergirl will likely follow suit too, distancing itself from the Snyder Superman saga and charting a new course. At the moment this whole connected universe is a bit of a mess, but DC seems to have found a formula that works, and hopefully, they can get the universe cleaned up enough that when these heroes finally do come together somewhere down the line it makes sense.