I don't think he's that shitty of a character to be uranus.
2
Seriously though, I would still doubt it. We know that Pluton and Poseidon are vastly different in forms and capabilities, so I doubt Uranus will be another case of the weapon being in a human incarnation, especially when its isolation from the plot thus far has been building up to it being a far different beast altogether. I'd say it's likely Dragon could have knowledge on it, but that's about it.
I'd say the giant Straw Hat from the Reverie is far more likely to have ties to Uranus.
As for Dragon's weather abilities, he has yet to show discernible proof of them being one filler line. As SSJ2 said, having him being able to control all types of weather would seem a bit much for just one Devil Fruit if it essentially packed the abilities of many into one. Whilst I would've speculated Dragon to have caused the lightning bolt prior, the amount of reverence placed on Luffy's top level
plot armour luck by several characters throughout the story's run would mean it could easily just be a coincidence at this point.