Jon Hamm, your phone's a'dingling!
But this is exactly the approach I'd hope they'd take with bringing in a new Batman so fast. Have him already be an accepted mainstay in this universe, tell it from Clark's perspective, have Bruce be a bit grizzled and jaded, almost looking at Superman as an unwanted, adversarial force for Gotham after that happened to Metropolis in Snyder's first film. Completely subvert audiences view of Batman on a dime. They're already going to be wary that it's all of a sudden not Christian Bale, why try to win them over the same way Nolan did?