according to Mr Klarman(see the NYTime article) this automation trends lead to more inefficiency in markets not less and thus give opportunities to some traders to bet long term in the other direction..
Or are those disrupted jobs just getting re-deployed as new trading businesses betting on some long term stuff..
He also said the increase in passive investment relying on the efficient markets hypothesis (EMH) will eventually lead to mispricings and inefficiencies that can be taken advantage of by active investors such as himself.
Those two things have nothing to do with the automation of execution trading and market-making. So he is not claiming that automating the execution trading and market-making done by banks in highly liquid markets (equities in OP) will lead to more inefficiency.