>>58141398
I get that it's fun to try and make these sort of connections, but trying to figure out an official canon in a series like pokemon is just picking arbitrary points and deciding they are enough for you to believe them to be true.
For example, this is a completely different Cosmog than Nebby. To assume that all Cosmog can only become Solgaleo is a wild assertation. After all, if the 'canon' is the true version then there is no 'canon' where it can evolve into Lunala which means the pokemon could not exist.