The pitch angle is interesting, apparently more than one writer was asked to pitch for various books, but some people (like Clevinger) weren't told it was either a pitch for the book in question or that there was competition, leading some writers to believe they were on books that were still 100% up in the air (like Firestorm), as evidenced by these tweets:
Brian Clevinger: You’re on Firestorm? Now I don’t feel like shit about losing it. Treat those guys right, they’ve had it rough
Gail Simone: Awww, I didn’t know YOU were the other guy pitching! You would have kicked ass! But thank you for the kind words! Guys, Atomic Robo by Brian Clevinger is one of the cleverest, funnest comics going. Highly recommended!
So this makes it clear that either DC told Simone she was competing against other pitches but not Clevinger, or Clevinger just didn't understand the deal as he'd already make it clear in interviews he thought he was on Firestorm in the future.