If the US starts buying BTC, we should expect other countries to follow. But, I doubt the Fed will resign its position that easily. In my opinion, until we see the actual bitcoin reserve plan in action, we should remain humble.
Every time some moderately wealthy country tries to escape the clutches of the world's centralized banksters, they send the US to bomb them into the stone age. Syria, Iraq, Libya... So, if the US succeeds in removing ourselves from their clutches, who are they going to send to bomb us?