Two weeks ago I was on the set of Justice League where I saw many of the superheroes in costume. As for the ones I didn't see in costume, I did see their costume designs (or in the case of Aquaman, the costumes themselves) and I can tell you that the recently released concept art for this movie - attached to the Batman v Superman: Ultimate Edition director's cut Blu - don't match what I saw.
It's really specifically Flash and Cyborg who don't look in this picture like how they looked on set. Flash looks NOTHING like the Justice League version of the character I saw in person, and this Cyborg is way more streamlined. I'm going to go out on a limb and say that this concept art is very, very old and doesn't reflect the movie at all. Alternately, this could be a look at Flash and Cyborg's outfits at the end of the movie, when the whole team has come together and they've been upgraded.
Either way - as someone who has laid eyes on the Flash and Cyborg outfits, these ain't them.