Hmm, not the most inspired choice. I really liked Warrior. Didn't see The Accountant after hearing the mixed reviews. Haven't seen much else from him.
Matthew Vaughn, when asked about what he's working on next: "I am planning another Kingman, I’ve written the treatment and some of the scenes…I don’t know what I’m going to do next but I have had chats about Superman, I love Superman." https://www.heyuguys.com/matthew-vaughn-superman-director/
From an interview with Collider. Basically what he's said before, I think. Matthew Vaughn Teases His Potential Take on ‘Superman’ as “Heroic” and “Feel-Good”
Repeat after me: "DCEU's Iron Man" Gal Gadot's WONDER WOMAN Has Seemingly Been Confirmed To Make An Appearance In FLASHPOINT
I figured this would be announced soon due to the success of Wonder Woman and the Batman trilogy being planned.
The "DC Extended Universe" Is Not An Official Title From Warner Bros.; In Fact, It Originated As A Joke