Trump did it, so frankly it's probably just a brain fart.

However, the US having a strategic reserve of a currency makes it a lot like other currencies. The next logical step is that banks can use it (already in the works - also Trump). If you can get a bank account it bitcoin, the next logical step is towards a fractional reserve system (loans, banks effectively "printing money"). The strategic reserve can cover a run on banks - think interbank lending, bailouts. Then the fed can offer bonds and IOUs (fiat).

All the things q lot of bitcoin advocates say bitcoin should stop, but you can't stop the government writing an IOU and demanding everyone treat it as currency.