Man of Steel 2 has somewhat fallen by the wayside it seems with DC and Warner Brothers more interested in the world building of the DCEU than giving Superman a second solo outing.
It does seem as if there is something in the works though. Speaking to Hey U Guys recently at Arrival junkets, Amy Adams revealed that a Man of Steel 2 is indeed getting worked on at some level. She said:
I read about Man of Steel 2 when you did. Lots of times I find out after the fact, which is fine. It's completely normal. It's not indicative of anything, but yeah, I know they're working on a script and I know it's in the works.
I think there is a little too much in the works for the franchise right now for it to focus solely on another Man of Steel film, that and, well, Clark Kent is currently "dead". But I'm sure at some point we will get back to it.