A billion may be a lofty goal, but I don't think those movies are going to be much competition. First of all, Us is going to have been out for two weeks before Shazam comes out, it's for a different audience too. Hellboy, again, an R-Rated movie is not the family film that this is. You have to remember, we're not the people that make these movies billion dollar tentpoles. While Hellboy is a movie that makes us take notice, I can actually see it being a flop unless it gets insane word of mouth.
But Aquaman was up against a lot more as a Christmas release. I could see Dumbo giving it a run for its money, but I think Shazam is going to be a hit. DC clearly believes in it by ending the embargo two weeks ago and setting up early showings. Again, I think a billion may be tough, but I think it'll have a great showing.
Dumbo is probably it's only shot at real competition.