Eh. Doesn't work for me, besides, I have my own theory.
If Roger had this Ancient Weapon, doesn't that make his achievements pretty lacklustre? Roger didn't achieve becoming Pirate King through his own merit, he just ate a devil fruit as powerful as one of the ancient weapons.
How did Roger eat a devil fruit that's supposed to be hidden by the ponegylphs?
Finally, why should this particular devil fruit be considered on par with the other ancient weapons? Enel planned to destroy an island, Whitebeard had the power to do so also. If the only thing that makes Uranus, named after the god of the sky, worthy of being an ancient weapon that it can create waves, doesn't that step on the toes of what should be the weapon named after the god of the sea?
Personally, Uranus is most likely related to the moon people. Uranus is the god of the sky and people from the moon (in the sky) with many descendants living on sky islands. They had ancient advanced technology with one of the tribes close enough to the Ancient Kingdom for them to protect one of their poneglyphs.
Plus Oda seems to like robots. Uranus vs Pacifista vs Franky battle!