Godzilla-Movies.com:

The future of the series and its forwarding developments are very conscious of the method of "shared universe". Godzilla, Mothra, King Ghidorah, etc. could all share a single world view much like a Marvel movie where Iron Man and the Hulk can crossover with each other. It is said that each movie can be a possible film production where any one of them could lead a film of their own as the titular character.
Who would've thought that this was the next big cinematic franchise?

Not sure how it will work alongside the WB “Monsterverse”, built around 2014’s Godzilla and last year’s Kong: Skull Island.

Also of note from that article, a bummer for fans of Shin Godzilla:

Shin Godzilla was a huge hit, but instead of thinking of doing the obvious idea of making a Shin Godzilla 2, instead think about a world that can be used for a long time, I'd rather make a World of Godzilla.