If I had to take a guess, it's an extremely literal, surface level minded view of what is "Ruling class". In this instance, to be "Ruling class" would be anyone directly a part of the state with any form of jurisdiction to make policy. Everyone else is "working class", which means Jeannie McLane, one of the 5 people on your local school board is "ruling class" because she's part of "the government" and has jurisdictional power (albeit, very very limited) while Elon Musk is working class because he's not part of the government and has 0 impact over it