[trebleshot]

The quote they read was from The Dark Knight Returns. But Snyder specifically said they weren't adapting it as the next Superman film. They were just using it to hint at their future project, which is most likely a team-up movie. And honestly, I think that is a good way for them to help build up to a Justice League film, especially if they hope to compete with Marvel at the box office.

And I doubt Bruce would underestimate what Clark is capable of under any circumstances.