That's because Captain America: Brave New World brings adamantium into the fold. The substance shows up in the body of the Celestial that emerged from the Indian Ocean in Eternals. Now, it's the cause ...
Brave New World debuted adamantium in the MCU, which wasn't always the plan for the precious metal and its consequences.
The brave new world that Captain America inaugurates requires a better metal, a metal like adamantium. That will become even more apparent when adamantium gets bonded to Logan’s skeleton ...
No Weapon X yet, but Captain America: Brave New World marks the arrival of adamantium to Earth-616 ... That said, the metal that covers Wolverine's skeleton had an entirely different origin ...