The first Shazam! movie featured a brief appearance from Superman (we only saw the character from the neck down in the final shot), and it sounds like The Man of Steel might return for a more substantial role in the upcoming sequel - this time with Henry Cavill in the cape.
According to That Hashtag Show, Cavill "is listed as a member of the cast" of Shazam! Fury of The Gods, though they don't provide many more details.
It was reported in June of last year that Cavill had made a new deal with Warner Bros. to return as Superman in the DCEU, but that was never officially confirmed (the actor downplayed it in subsequent interviews). At the time, we were told that there were no current plans for a direct sequel to Man of Steel, with Supes expected to make a series of smaller appearances in other characters' movies.
So, a role in Fury of The Gods would certainly make sense, and since the source has had quite a few scoops pan out in the past, this is well worth keeping an eye on.
Plot details for Shazam! 2 are still under wraps, but we do know that the sequel will feature more of the Shazam Family, and is expected to introduce some "unexpected villains." Zachary Levi will return as the title character, with David Sandberg back in the director's chair.
Shazam! Fury of The Gods is currently scheduled for release in 2023.