I do hope they have an extended cut to reintroduce some more expanded material, but I don't hope that it's just Snyders version since I don't think that would work. I'm not sure how much they actually "finished" the cut scenes though, to know whether an extended cut would be feasible.
I haven't seen the movie yet, so can't speak to actual film, but I think it'd be easy enough to have the Flash and Aquaman without full background for them, if they weren't taking a lot of time to highlight off-scenes for them otherwise. I know I'm phrasing that badly. If they waste a lot of time on various Flash stuff without explaining who he is, where he's from, that's bad. If they establish that the universe has a number of metas, I don't think they need to explain everyone with an origin story. If you never saw Flash out of his mask, he'd just be the Flash, no need to say whether he is Barry or Wally or anything.The only reason I wasn't lost, was because I'm a huge DC fan. I went to see this movie over Thanksgiving weekend with three other people, and I spent almost an hour after the film answering questions to help fill them in on what was going on. That's not a good thing for a movie.
Cyborg, from what little I know, is integral to the Motherbox/ Invasion plotlines and needs his origin tied into it.
I think the only way I can explain it is that Superman detractors often say Superman is boring because he's so powerful. Superman fans point out that it's about who he is, and the power levels play off that and of course there's plenty of other characters on his power levels.until Superman showed up. Holy. Shit. I mean, come the fuck on, couldn't he have been more than just a minor inconvenience to Superman?
If you have a person in charge of Superman that doesn't GET Superman, that doesn't like him and understand him, then you get a brooding alien, unable to empathize or interface with humanity and unequaled in power except by those like him (fellow kryptonians).