Multi-national corporations as pseudo central banks is likely one of the many end points of globalization. Much like globalization, it is neither good nor bad, it just is - and is so for reasons of inevitability.
The nation-state was always a sort of imagined reality. Though, I'm uncertain much can be drawn from that fact.
TransferWise already allows me to hold a plethora of currencies. Does that make them a central bank? No, just a financial OS. Central banks back currencies, everyone else is just a service provider.
How is issuing a crypto currency backed 1 to 1 to USD with reserves acting as a pseudo central bank?
not yet it's not, but once upon a time, the dollar was backed by precious metals. Not a terribly outrageous leap.