You haven't seen goku since dbz or watch at all but goku is now so godly powerful that he can destroy the universe... I don't think you did your full research and stopped at frieza. Vex can turn a planet to a machine but whatever planet they turn, goku will destroy if we go by lore logic the Vex will not understand how a mammal like being is able to destroy planets with ease and have a durability to hold a supernova attack in his hands twice and like history shown us, they will worship him. He will have no need to fight atheon, Atheon will bow to goku as we seen before with the heart. You need to get your homework before you start spitting none facts like the one where the Vex cannot interfere with time outside the vault only go too and from outside.