The actual press release makes it clearer that this isn't a lockout of any kind and there's no direct government involvement. Softbank and some of other banks persuaded by Softbank are ponying up $500B for OpenAI to invest in AI. Trump is hyping this up from the sidelines because "OpenAI says this will be good for America". It's basically just another day in the world of press-releases and political pundits commenting on press-releases.