Needed a bro high five at the end...

They weren't friends but I think the ending showed that they realized they didn't have to be enemies.

They need to come up with a way where both Godzilla and Kong acquire the power of speech so its easier to know whats going on. Plus the humans can communicate with each titan. Also this could pay homage to the scene in the original Gidorah, the 3 headed monster, where Godzilla sits on a rock while working out his differences with Mothra and Rodan

OMG, I almost thought that was going to happen. It would have been hilarious if it did.