This I think is a better explanation: https://thehill.com/policy/finance/3786962-ftc-orders-master...

The point is I believe, the payment can be settled outside of the mastercard network, but mastercard only allows their service to perform the mapping between token and PAN, and force settlement to happen over the mastercard network. The idea here is that the token can be taken by another card network, mapped to the real PAN, and then settlement happens between the issuing bank and merchant over the other network.

I.e. instead of acquirer <-> mastercard <-> issuer it becomes acquirer <-> X-Network <-> issuer, even though Mastercard was used to create the initial link between device and bank account.