The article does answer the question 'why should managers exist' (to direct the subjective so the enterprise's limited means move towards its goals in the absence of enough AI smarts to know what is good right now).
I went into it expecting a 'rah rah fire all the managers' potboiler and was pleasantly surprised.
What I do wonder though is, businessman to businessman, how much of our economic activity really does operate in the academic 'free market' principles this article leans on...and I think that the answer to that question directly drives the application of this article's follow-up question at least to my mind: "will AI eat manager jobs too?" and the answer is murky even to me.
I think reputation, ego, feelings/sales, habits and circumstances have unaccounted for influences on the free market, to say nothing of the 'businesses want to capture the market, government wants to regulate the market, consumers want to eat the market' bigger non-academic forces at play we've all discussed so often in the past.