Bueno de Mesquita makes a compelling case for modeling most corporations as dictatorships in The Dictator's Handbook. So as long as succession is planned at the Corp, then yes, I suppose monar hy would be the correct model.
But Apple is not a monarchy and the size of a company even protects a CEO in the western capitalism. A CEO of a startup may end up in debt and without a company if bad decisions are made. A CEO of a huge company will usually be let go with a sufficient good bye pay and an outlook for another job (or he blames somebody else and never leaves even if guilty).
Is it some kind of monarchy?
PS. It's not the largest. Neither by market cap nor by employee number.