Superman is the centerpoint, via Man of Steel. They needed that to work (and it did... enough) in order to move forward. Batman v. Superman (fucking stupid name) is more or less a Man of Steel sequel, but they're absolutely selling it as a Batman movie w/ Superman in it. Which it might have become once Affleck got Terrio in there. It's still hard to tell whose movie this ultimately belongs to, even though the basic structure of the film's been out there for awhile thanks to Faraci having read the script and basically laid out the major plot beatsnothing surprising at all, considering who is in the film and where it has to lead to. But nobody's going to this thing for its fucking plot anyway.
But this movie doesn't happen unless Man of Steel happens, and key aspects of the film's universe are rooted in that. The climax of that film plays heavily into how and why people are doing what they're doing in this one. Everything traces back to Superman's first day on the job in Metropolis, basically. he's the bullseye at the center of this universe.
BUUUUUUUT: It's entirely possible, if the WB as Reactionary Executives narrative does hold true, that they're nervous about this version of Superman they're putting forward being that anchor, especially when confronted with a Batman in Affleck who is consistently bringing them successes both critically and financially, and the reaction to Suicide Squad, which is very much Batman-centric without actually being a Batman movie.
It becomes a question as to whether Warner Brothers has decided to short their own investment in Superman.