If re-metalisation of exchange is looked at in isolation, then its typically about a Level Two in Dmitry Orlov's model of de-complexification.
Bitcoin's concurrent use beside fiat could lubricate the change and keep it to a Level One, even.
But I don't see The Powers That Be handing over the levers with a smile and best wishes for our future. They can force it to be a Level Three easily enough, and a Level Four in places.
Orlov: Five Stages of Collapse - https://cloudflare-ipfs.com/ipfs/bafykbzaced7utzqscshd7uypprb7wubgu4grff33zn3obynsljrfbhpb3ivne?filename=Dmitry%20Orlov%20-%20The%20Five%20Stages%20of%20Collapse_%20Survivors%27%20Toolkit-New%20Society%20Publishers%20%282013%29.pdf