The_Red_Queen didn't say it had better properties, only the description and name change 🙂
It goes from "Light Crossbow +1" to "Sharran Crossbow", both have the same stats (
https://baldursgate3.wiki.fextralife.com/Sharran+Crossbow).
But, in my opinion, a History skill check could help the character remembering that the weapon was used slightly differently to be more efficient, potentially. Not advocating for that to be a thing, but I could see it.