From the looks of things, a Godzilla vs. Rodan movie may have been under serious consideration. Plans for an unmade Godzilla-King Kong crossover indicate that Toho may have been eyeing Godzilla vs.
Godzilla x Kong: The New Empire debuts a Baby Kong known as Suko ... confronting Titanus Rodan and Ghidorah alone, sacrificing herself for the sake of Godzilla and humanity.