What are Bastion's birds' names?
We don't know.
We can speculate all we want, but in reality there is no given name for any of those alternate birds.
It can be assumed regardless of the bird's species, the name is still Ganymede. I have tested out the "Ganymede" highlight intro with each of the different skins, and in each result, the text produced after scanning the bird is the same. Although it may be producing the result "Bird" in whatever the Omnic text might be, it seems to be identical throughout.