According to Den Of Geek and their sources, Man of Steel 2 is on a permanent hold, even though Warner Bros. has already announced another Superman standalone in their official press release for their slate of DC movies.
In a massive expansion of the Studio’s DC Entertainment-branded content, Warner Bros. Pictures and New Line Cinema will release a slate of at least 10 movies—as well as stand-alone Batman and Superman films—from 2016 through 2020 that expands this prized universe of characters.
Dan of Geek reports the permanent hold for Man of Steel 2, when covering the rumor news of George Miller being attached to direct the film, which they say their sources informs them that Miller is in talks with Warner Bros. to direct a DC Extended Universe film, but which of the films hasn’t been decided on and another source tells them that from what they understand Man of Steel 2 is on a permanent hold:
We’ve since heard from two sources that there might be substance to this rumor. They tell us that Miller is indeed in talks with Warner Bros. about the possibility of taking on one of its future DC movies, though exactly what that movie is hasn’t been decided as yet.
One source said that what Miller directs will depend on what story most interests him, his take on it, and everyone’s availability.
While this doesn’t rule out the possibility of Miller taking on Man of Steel 2, another source has said that, as far as they understand it, the sequel is on “permanent hold.”
We personally have a hard time believing that Man of Steel 2 is on a “permanent hold”, because the word “Permanent” means — remain, unchanged, indefinitely. A highly unlikely usage of word or title Warner Bros. would put on one of their biggest franchises, like Superman.