With Banner and Hulk's merging cutting back on Hulk's strength significantly in exchange for increased self-control, Thor and Captain Marvel are officially the MCU's most powerful superheroes. So it's only natural that the two would - at some point - team up to take out an incredibly powerful threat. After all, as any fan of Marvel Cosmic will tell you, Ego the living planet isn't even in the top ten of the biggest fish in that sea.
Whether it's the first appearance of Galactus, getting trapped on the planet Sakarr (where every inhabitant is as strong as the Hulk), or any other number of cosmic beasties, there are plenty of challenges for Carol and Thor to throw themselves at until it dies. On top of that, them meeting would actually be really simple, now that Thor is running with the Guardians Of The Galaxy.
Seeing the two biggest wolves in the MCU's woods constantly competing on who can out-badass who would make for a truly hilarious adventure movie.