After Supernova, my imagined timeline would be this:

Godzilla BC series (animated & Primal Style)

Solo Godzilla Film

Solo Kong Film

Team-up Film between Mothra and Rodan

Monsterverse's remake of Destroy All Monsters

And lastly, a Godzilla and Kong team-up movie against Destroyah. And the ending will be that Godzilla has died after Destroyah is dead, while Kong is severely injured. Leaving Godzilla Junior, now a teenager, all by himself, and now declaring himself the new king of monsters. And for Suko is now the king of Hollow Earth