[Spoiler alert]
…the Marvel Family.
This is actually heartening. The Shazam aesthetic has always been, ah, different from that of the rest of DC’s (to say nothing of Marvel’s). I’ve seen it handled properly by Brave and the Bold, but I’m not entirely confident that the modern era is really able to do the character properly. Having the rest of the Marvel Family be in the film argues that they’re conscious of the source material. That’s not nearly the problem that it has been in the past, but it’s still there.