Hollywood has become a funny place. Actors saying they'd like a role has become news regardless of whether the studio is interested in them or not. So when someone like Josh Gad (Beauty and the Beast) posts a random picture of a Batman villain… some folks think that maybe there's more to it.
— Josh Gad (@joshgad) May 2, 2017
But… there MAY be something more going on. Recently Gad has gained some followers of interest: DC Film Execs Geoff Johns and John Berg. Both Johns and Berg started following Joe Manganiello just before he got cast as Deathstroke and Rick Famuyiwa before it was announced that he was going to direct the Flash.
At this point things seem so up in the air with the future DC films, between Famuyiwa leaving the Flash and Manganiello not sure what's going on with the director change on Batman… I wouldn't take anything as fact until the films start to shoot. And even then things might change.