If US goverment sell BTC who buy it?, the people? if this yes, so the BTCs returns to the communitty and with that the "power" so.... if the government its really against the BTC its not better for them to confiscate them and never sell? and dont show you like another player in the game?
That tweet is fear mongering at its finest. He assumes that if gov sold x BTC and owns 10x BTC, it's going to sell that 10x and it's going to sell it all at once. We don't know if, when and how much of it is going to be sold, but he's telling everyone that it's going to lead to 10k. He's spreading FUD probably as he's shorting bitcoin with leverage.
The governments can buy as much BTC as they want because they can print money but it's better for PR not to do so and instead sell bitcoin. They used to do it on auctions but during the banking crisis it's better to put pressure on BTC so it doesn't look as tempting.