I'm not convinced that WWE is intent on having Batista walk out of WrestleMania as champion.
If Guardians of the Galaxy isn't coming out until August 1, why do most people think WWE is hotshotting the title on Batista at WrestleMania? Right now he's only scheduled through Extreme Rules and considering his limited dates will probably not be scheduled for the mid-to-late May European tour, meaning if he has the belt he'd be missing approximately two weeks of dates, including the Raw/Smackdown in England.
I am assuming WWE wants Batista to walk around with the title during promotional appearances for the movie like The Rock did last year, so wouldn't it make more sense to put the belt on him at Money in the Bank (June 29) or Battleground (July 20)?
This entire Batista deal is crossing the line more every day from mere disaster into hilarious unintentional comedy, and the payoff will be the WM crowd shitting all over his title win like no other match. You're right, the entire thing makes no sense on several levels, especially since no one knows how the movie is even going to do and the guy that's supposed to be the FACE OF THE WWE after Wrestlemania is doing one quick segment a week and not even being allowed to talk. You just can't buy entertainment like this.