...For those bones to still be there on the surface after so long, that world must have no wind and no rain. The world must be utterly sterile.
The implied mutual destruction on top of that... Walking on the surface of that world would break people. It'd be utterly silent except for the sounds of people stepping on bones. There would be nothing living, plants or animals. The only reason the planet has an atmosphere would likely be the Tower.
This wouldn't be a Tomb World, it's past that. It'd be a Grave World. Where nothing lives and only the Tower remains. Still standing. As it was before it lured those civilizations to their deaths. And as it will be after your civilization joins the multitude of bones.
It'd develop it's own mythology and most people would see either the planet or tower as cursed.
I have a colony with one of these towers. Please, don't spread this rumors near there, ok?