I'm the one responsible for letting loose the news that Bryan Cranston was cast as Lex Luthor for Batman Vs. Superman.
Someone who works close to WB filled me in on the info.
Originally, I was told the big announcement was going to go down following the series finale of Breaking Bad.
However, the announcement never came.
Questioning my source, he/she said Bryan Cranston ended up turning down the role of Lex Luthor in the movie (source also filled me in that Mercy Graves would be in the movie, Wonder Woman, etc).
Eventually, Jesse Eisenberg (not Heisenberg) was cast in the role.
We also know the Batman Vs. Superman script was tweaked to accommodate Jesse Eisenberg as Lex Luthor, which obviously means the original David Goyer script featured an older Lex.
While filling EW.com about Jimmy Olsen in Batman Vs. Superman, Snyder mentions that originally Jesse Eisenberg was going to play the role of Jimmy Olsen; the article mentions at that point WB was still interviewing actors for the Lex Luthor role noting most of them were older and imposing figures "such as Breaking Bad star Bryan Cranston."
A little spin ensues as it's mentioned WB "decided to take a chance and experiment with a younger, weirder, and more frenetic Lex."
Actually, what probably happened when Cranston changed his mind, they decided to go in a different direction with Lex. Chris Terrio was brought on board to rewrite David Goyer's Superman Man of Steel 2 script (with Cranston as Lex), and they came up with the "crazy" Lex idea.
Snyder said the following about Cranston:
“We talked about the usual suspects that you would imagine; any actor who has been bald, probably,” Snyder says. “Bryan Cranston would have been great, right? And by the way, he’s an amazing actor. Can you imagine how different the movie would be?”
Yes, Zack. Batman vs. Superman would have been different, indeed.