I was expecting both Rodan and Mothra for this film because Rodan doesn't have an interesting enough backstory for his own movie (see Godzilla vs MechaGodzilla II), but I was hoping for them to save Ghidorah for a Ghidorah The Three-Headed Monster remake. That film was kinda the Avengers of its day, teaming up Toho's three best monsters at the time against a new threat. They could even throw in Kong this time. Ghidorah was only ever a Godzilla movie in the same way Avengers is an Iron Man movie.
Instead, Rodan, Mothra and King Ghidorah are all probably going to share Legendary Godzilla's backstory as creatures emerging from beneath the earth, and they're all going to be uninteresting. It's something I always hated about GMK: Baragon, Mothra and Ghidorah were interchangeable. Rodan was always a less interesting flying Godzilla, but Mothra was the current incarnation of an ancient psychic living god on a secret island that communicated through two fairy twins; and Ghidorah was this unstoppable cosmic force that had decimated countless planets in the past. Without that backstory, all they are is men in funny suits. It already bothered me that Legendary Godzilla wasn't created by nuclear bombs, which was kinda the reason his first movie was ever made.
Also, unless they're saving some more monsters for Godzilla vs Kong, it's going to be a really low stakes fight now.
