I fell off on viewing anything from film vlogger John Campea. So earlier this month he discusses whether or not there will be a Justice League sequel. And goes through the reasons it may or may not happen.
I liked Justice League when it came out last November. Unfortunately it didn't meet financial projects, didn't even come close to the Avengers films. It was cool to see Batman, Wonder Woman, Cyborg, Flash, Aquaman, and Superman team up to face off against Steppenwolf. It was a great movie, but I recognize that the performance of other DCEU films - Wonder Woman excepted - only served to further depress excitement this team-up movie.
With that said I'd rather hope they don't reboot give this franchise some more time to develop. Aquaman will debut in his own film during the holiday season and hopefully that will be a movie that will draw people as Wonder Woman had. I still hear news about a standalone Batman film and it's about time even if Batman vs. Superman - which I also liked - was an uneven debut for the "Dark Knight" in the DCEU.
As far as a reboot - which I hope doesn't happen, yet - what if they did something similar to the Joker. That film is expected to be outside of the DCEU with no connection with Man of Steel, Batman vs. Superman, Suicide Squad, Wonder Woman or Justice League. So that could be one direction to take it without dismantling the DCEU. Then again I had to say as of now, they shouldn't do it yet!
Finally, with the upheaval over who plays Batman - if Ben Affleck is expected to leave that role. Or as mentioned in this video Henry Cavill might be out as Superman, but Campea doesn't buy it so who knows where the news is on that.
All the same, when will be see a new Justice League movie. It's definitely not a matter of if, but when. The Avengers franchise - even if the latest installment leaves me unsettled in some respects - is doing as strong as ever so I could believe DC and Warner Bros would want to compete with that. The only other superhero team-up group is DC's Justice League!