Campaigning for movie roles never works (if someone can prove me wrong, go ahead as I don't remember any actor getting a role because he publicly said he wanted it) so Cranston most likely won't be playing Mr. Sinister.
... you may have heard of an actor named Channing Tatum and a character that often goes by Gambit...

There are actually a few. IIRC Sam Jackson ended up in the prequels because he asked to have a part. Lots of actors have done animated television shows after campaigning for a part (The Simpsons had multiple instances of this).