I'm not necessarily happy with this move but I can see why they've done it from a business point of view as they seem to have removed the Cyborg film in the process, maybe to test the audience reaction to him in JL and Flashpoint. But yeah, I agree with those who are annoyed at getting Flashpoint yet again. Why couldn't we get a full on Rogue's story? It just seems way too early in this universe, but I understand people saying that they'll be doing it to fix problems already apparent in the universe. So yeah you've got the presumed cancellation of Cyborg to test him in this and to fix the problems of the universe it makes sense for them.
Now, interns of what they'll do with the story I wonder how much they can do? Who are they going to bring back? So we need Flash, Cyborg, Aquaman and Wonder Woman. Are they going to First Avenger Henry Cavill and make him look small or recast with a similar looking actor? I'm quite looking forward to Jeffrey Dean Morgan and Lauren Cohen as Batman and Joker. Then there's going to be all the other roles. Who are going to make up the rest of the heroes? It'll be cool to see them maybe bring Cara back as Enchantress. Maybe bring back other members of the Suicide Squad as heroes instead of casting new people, or maybe put them on others teams. Like putting Croc with Aquaman instead of doing Aqualad and Garth being in his army. When you think of what they're doing in terms of story it seems like this is going to be the most difficult to get right, even more so than Civil War. If they alter the story like they did in the TV show or how Civil War did they will get torn about. Try and follow it faithfully they'll it's going to mean and awful lot of new characters being introduced and it not really being a Flash movie anymore. Or if they condense it down to just a few key characters they'll be criticised for cutting down and missing parts, like if they cut out all of the British underground movement.