He isn’t court packing, yet. And probably won’t.
It does however do at least two things: It appeases some of his supporters that want to pack the court and it puts pressure on the Supreme Court to modify their rulings to fall in line with the agenda of the current administration which is exactly what Franklin Roosevelt did and he got the results he wanted by doing so.
Either way, it puts doubt on the Supreme Court, makes it appear more political, and undermines the belief in the rule of law.