You could be right.

https://en.m.wikipedia.org/wiki/Bourgeoisie

The bourgeoisie are a class of business owners and merchants which emerged in the Late Middle Ages, originally as a "middle class" between peasantry and aristocracy.

It is possible that the meaning of "middle class" has changed. So Musk is middle class, but the lawyer or pizza shop owner are not.

Edit: shit, I should have read farther. Bourgeois is used in multiple ideologies.

https://en.m.wikipedia.org/wiki/Communism

The two classes are the proletariat, who make up the majority of the population within society and must sell their labor power to survive, and the bourgeoisie, a small minority that derives profit from employing the working class through private ownership of the means of production.