They were considering having Bill in the movie, even Balder, they were thinking of doing a proper Ragnarok movie but Feige ultimately gave in to his producer and Marvel fans screeching for a Planet Hulk movie.
>“You had the big scoop about us doing ‘Planet Hulk,'” said Feige. “It turned out to be accurate [but] at the time, it was not accurate because we didn’t have any plans to do it and Joss (Whedon) was doing ‘Age of Ultron’ at that time. The way it ends as you recall with Hulk in the Quinjet going off, right?”
>Feige continued: “We said, ‘Joss, we can’t do that because he’s not going into space and people are going to think we’re doing ‘Planet Hulk’ because Umberto has some big hot scoop that we’re doing ‘Planet Hulk,’ we can’t do it.’ He goes, ‘Well, what are you going to do?’ We said, ‘We don’t know.’ So, if you go back and look at that shot of the movie, he’s in the sky. It’s blue sky.”
>At one point, the script called for the Hulk to be detected near Saturn — but Marvel changed it to keep its options open. “So in the movie, it’s, ‘We lost the signal out by the Caspian Sea.’ Or something like that, it was all earthbound. “
>So why did they ultimately go the “Planet Hulk” route?
>“We wanted to do something totally different with Thor,” Feige said. “Chris Hemsworth really was like, ‘When do other Marvel players come in with me?’ … Definitely, [we] want Hela in the movie. Definitely wanted, of course, the continuing relationship with Loki. We had early ideas for Valkyrie. We were talking about Balder. We were talking about Beta Ray Bill, but, that’s not enough. But we were like, ‘We need something big.'”