It also delivers a none-too-veiled threat of political retaliation if "some states refuse to open," presumably at the figurative snap of his fingers.
The only political retaliation would come from the voters of that state. Trump's statement is unambiguous in that regard. There is no political retaliation from the government that is even hinted here.
Of course States should have no question about what happens to all the 'free' [sic] federal money that would be cut off once it is no longer needed. Nothing threatening about that, veiled or otherwise. It is simply common sense.