This is a really absurd assertion to make in February 2025. His close buddy is the upcoming NASA administrator, and he clearly has the President's ear.
Musk is a Presidential adviser without a bounded specific portfolio, he has say in anything that (1) the executive branch has a say in, and (b) Trump chooses to listen to him on; as NASA is one of the participating agencies in ISS, the US executive branch has some role in it, and Musk could potentially exert influence over that.
The contract to deorbit after the end of its operational life in 2030.
Musk wants to deorbit the ISS as soon as possible instead, after getting in a twitter argument with astronaut Andreas Mogensen.