Ezra Miller's The Flash movie is unlikely to begin filming until 2021. Miller made his (very brief) debut as Barry Allen in Batman V Superman, but didn't become a main player in the DC Extended Universe until Justice League. He was initially supposed to star in his own solo film shortly after that, with Rick Famuyiwa directing. Of course, this was before Famuyiwa parted ways with Warner Bros. over creative differences on The Flash, and Justice League went on to disappoint both critically and commercially.
Famuyiwa's decision to step down wasn't the first director change-up for The Flash, either, and the project has since passed through the hands of Game Night helmers John Francis Daley and Jonathan Goldstein. Following their own departure, the movie has now fallen into the lap of IT 1&2 director Andy Muschietti, and has Christina Hodson (Bumblebee) working on the script. However, even with a fresh creative team in place, the film has encountered yet another roadblock in pre-production.
In an extensive report on the status quo of the DCEU, Variety says The Flash movie is unlikely to begin filming until 2021. The problem isn't WB and DC, however, as the studios are said to still be firmly onboard with giving Miller's wise-cracking speedster his own adventure. Rather, Miller will be busy filming Fantastic Beasts 3 for a good chunk of next year (with production set to begin in Spring 2020).
Even with this new delay, there is a real chance The Flash will actually happen this time around. Muschietti and Hodson have already proven themselves to be reliable collaborators in WB's eyes, with the latter having also written next year's Birds of Prey (And the Fantabulous Emancipation of One Harley Quinn) and committed to writing the Batgirl movie after she finishes The Flash. There shouldn't be any unanticipated creative differences with them, in other words, unlike the previous filmmakers attached to the project. Further, they should be able to craft a Flash movie that satisfied both WB and Miler's demands, as far as the film's artistic direction is concerned.
It's possible the extended delay between The Flash and Justice League will even be to the former's advantage. Miller's Barry Allen is widely considered to be one of the best parts of Joss Whedon's cut of Justice League, so there's already a demand for more of him on the big screen. And by releasing further away from Justice League, The Flash may have a better shot at tapping into that demand without having any of the baggage associated with Miller's most recent appearance as the character. Then again, this isn't the first time The Flash appeared to be on the precipice of coming together, and things haven't worked out so well in the past. For that reason, fans might not want to start getting excited for this one just yet.