Are we still looking at a Batman/Superman movie with cameos, or is it JL?

I still feel the purpose of the casting for some of the superheroes will end up being small parts to show their existence and create the existence within their universe. When I see questions of "How will they juggle all of these characters?" it makes me wonder if I'm the only one seeing it this way. I would say it makes sense that some of the superheroes aren't even shown in costume yet. We just know these being with powers exist as Batman has been monitoring the phenomenon. Upon Superman being the first official superhero stepping out to the public eye, the two of them can bring together a team of people with abilities. Throughout the internet I've seen some people say "Don't call it Batman/Superman anymore, call it Justice League already" but I kind of think that's a jump to conclusions as much as any other idea at this point. If done correctly, it simply shows these characters exist and we won't need to retread as much origin wise.