There's no way it wouldn't have been. We're talking Disney here. Even if the movie itself blew or was average, it would have definitely made money at the box office. It's just how it works now. Every Marvel movie, post Avengers, has been a money machine. Even Thor made way more than its first part did. Same with Capt.
People were mocking me when I predicted this. Saying I was way off. In the box office bomb topic there were many people saying guardians would bomb hard.