As we’ve seen in the previous trailers, Freddy has one of Batman’s Batarangs, so not only is Batman someone kids idolize, he has his own memorabilia. It’s also fun to hear Freddy say “heroes fly” after the first Shazam! trailer, where Billy Batson was testing out his new powers and having difficulty doing much more than impressive jumping. To Freddy and kids like him, Superman is at the top of the superhero mountain, in large part due to his powers of flight.
Article source: https://www.cinemablend.com/news/2468759/new-shazam-video-references-superman-and-justice-league