In the sense that originally, the writers just threw a guy with claws on his gloves against the Hulk, and people liked it so Marvel said make more of this guy, but pretty quickly the writers decided that they didn’t want to say anyone could pick up the gloves and be Wolverine, so they decided that the claws were part of him and not the gkloves. And the Weapon X plot came around with the adamantium. I don’t know if any writer actually said that Wolverine didn’t have claws at all before the adamantium skeleton? It’s just that Marvel kept adding details just as new readers kept asking questions about how it works, and then Marvel suggested that Wolverine’s healing factor might mean he was actually very old, and then they said well what did he do before the adamantium skeleton, and bam, there’s the bone claws. It’s not even a retcon as long as no one said “no claw before the metal bones” before, that’s just how writing goes over decades most of the time, new things get piled on.