That might be perfect when Rey is looking at the stars and we hear the voices. Luke is rallying the troops to fight Papa Palps.
Oh, yeah, that could be great. Maybe john could also include some other jedi around luke like mace or qui gon (all the voices, in the scene only kenobi, anakin and luke of course, but at the moment luke calls the troops everyone could show up, maybe even leia, i think it would be awesome) also other oportunity is put there in the moment ben dies, so luke could “receive” his spirit and so ben can appear as a force ghost in the end scene.