Seeing as Godzilla and Pacific Rim are in the same family on the Legendary lot, all that would have had to happen was for Warner Bros and Universal to have played ball, and a trip across the dimensional rift could have seen Pacific Rim 3 help lead to a knockdown prize fight of epic proportions.
When we last left Pacific Rim: Uprising, the Pan Pacific Defense Corps was about to take the fight to the Precursors after foiling their latest efforts to exterminate all life on Earth through their Kaiju army.
Keeping that in mind, there’s a small hint as to how all of this Godzilla madness could have collided with the Pacific Rim universe, and it comes down to a word we all know and love: multiverse.