Surely it would be Greenwood's character that would have developed into Hunter's? 2233 vs. 2254 isn't it? That would seem more likely. Though nu-Pike's life was changed with Nero's shenanigans. Promoted to admiral away from Enterprise duty, and so unlikely to have the accident that put him in his beeper in 'The Menagerie.'
Having said that, I'm more a fan of the total reboot over the alternate timeline theory.